Why Red, Blue, Yellow and... Green?

[Surfing HalfOrc]

Something silly that's been bugging me. Many games are designed for four players: Candyland, Trouble, Sorry, etc, and they almost always use those four colors.

Then today I was watching a show where a prince and his three most loyal servants came forward in time. They had to change out of their period costumes and into track suits. The colors? Red, Blue, Yellow, Green.

Windows Logo? Yep, RBYG

I know Red, Blue and Yellow are primary colors, but why didn't purple or orange make the cut? :smallconfused:

Not a serious thread, just something I noticed... Feeling kinda random while waiting on Typhoon Bolaven.

[Eldan]

Depending on the colour system, green may also be a primary colour. And humans have receptor cells for green light.

[Serpentine]

Could have something to do with the fact that (most) humans can see more different shades of green than any other colour.

(I didn't know we have receptors specifically for green?)

[ForzaFiori]

Depending on the colour system, green may also be a primary colour. And humans have receptor cells for green light.

Probably this. Red, Blue, and Yellow are the primary colors of pigment, while Red, Blue, and Green are the primary colors of light.

[Emperor Ing]

I know very soon someone's gonna make a case for Cyan, Magenta, and Yellow.

[Logic]

Probably this. Red, Blue, and Yellow are the primary colors of pigment, while Red, Blue, and Green are the primary colors of light.
...that can be perceived by most humans.

[Anarion]

I would guess it's an issue of contrast. Shades of blue and shades of red often resemble purple and orange, whereas it's harder to go towards green accidentally. Probably because of the separate eye receptors as already noted.


Could have something to do with the fact that (most) humans can see more different shades of green than any other colour.

(I didn't know we have receptors specifically for green?)

xkcd. It's educational! (http://www.xkcd.com/1080/)

[Siosilvar]

I know very soon someone's gonna make a case for Cyan, Magenta, and Yellow.

Those are just not-red, not-green, and not-blue, so...

[Flickerdart]

Red, Blue and Yellow are the primary colours of nothing at all, because CMY are the primary pigment colours. Except Magenta isn't even a spectral colour but a fraud, being first invented by W. Henry Perkin in 1856. So RGB is the only true primary set, and you should really be asking yourself "why yellow?".

The answer, of course, is that the human eye is biased towards the warm colours, by which we are constantly surrounded (with the sun outdoors and incandescent light indoors). Also, if you look at the spectrum, an enormous chunk of it is basically just blue (of course, purists might refer to a part of it as Cyan, but Cyan is really just greenish-blue and doesn't deserve to be a primary) so after Red, Green and Blue there just isn't terribly much left. And frankly, if you told most people that mixing Red and Green made Yellow, they would call you a witch.

[Elemental]

And frankly, if you told most people that mixing Red and Green made Yellow, they would call you a witch.

Except if you're using paint, and then you get brown.

[Siosilvar]

Except if you're using paint, and then you get brown.

Since red paint is basically "anti-blue" and "anti-green" mixed together, and green is "anti-red" and "anti-blue", that makes sense. Paints are subtractive, i.e. they don't work by emitting light (which would be silly), but by not reflecting certain colors.

[Flickerdart]

Except if you're using paint, and then you get brown.
No, we just went over this, the painter's primaries are a sham and don't count.

[Heliomance]

Red, Blue and Yellow are the primary colours of nothing at all, because CMY are the primary pigment colours.

What makes CMY any more valid than RYB?

[Yora]

(I didn't know we have receptors specifically for green?)

The normal human eye has Red, Blue and Green receptors. Which is the reason all monitors use RGB colors.
Some people also have a fourth kind for Yellow, which allows to see much starker differences in yellow shades. (I think all are women, since it's a recessive gene on the X chromosome.)

However, someone mentioned that the human eye is able to see shades of green best (which is the reason nightvision devices are tinted green and not blue or red), but that is only partly true.
A huge difference is made by the way our language classifies colors. Here is a very extreme example (http://www.youtube.com/watch?v=4b71rT9fU-I#t=3m) of a culture in which people can easily tell apart the difference in two almost identical shades of green, but are unable to tell blue from green.

[The Succubus]

Because when they were working on Pokemon Pink, a lot of the creatures had some very...curious...shapes. If you catch my drift.

[Iruka]

No, we just went over this, the painter's primaries are a sham and don't count.

Doesn't change the fact that you do get brown when mixing green and red paint. :smalltongue:

[Asta Kask]

Because when cultures make color terms, these are defined even in cultures with few color words. Like this. (http://en.wikipedia.org/wiki/Color_term#Basic_color_terms)

I don't know, but that could be it. The Stroop test also uses Blue, Red, Yellow, Green so it's not restricted to games. Maybe these colors are seen as more 'basic' than others?

[willpell]

On the topic of color geekery, I've always kind of rolled my eyes at the idea that the rainbow includes Indigo, but I've semi-recently come to the conclusion that I consider Gold to be a distinct color between Orange and Yellow. The rainbow doesn't agree with me, but I'm not one for taking my cue from nature anyway. So for my purposes, there are eight primary and secondary colors.

[Winter_Wolf]

Paints are subtractive, i.e. they don't work by emitting light (which would be silly),

That would be awesome.

Also, green, because green is the best color! :smallwink::smallbiggrin:

[Yora]

On the topic of color geekery, I've always kind of rolled my eyes at the idea that the rainbow includes Indigo
It is because Newton wanted seven colors because seven is cooler than six.

[Tyndmyr]

Why not? They're visually distinct, even in poor light.

Additionally, red and green are color opponents, as are blue and yellow. So, regardless of which triad you start at for prime colors, opponency theory has the answer for you.

[Heliomance]

A huge difference is made by the way our language classifies colors. Here is a very extreme example (http://www.youtube.com/watch?v=4b71rT9fU-I#t=3m) of a culture in which people can easily tell apart the difference in two almost identical shades of green, but are unable to tell blue from green.
The case was clearly made that they can tell the greens apart far better than the green and the blue, but I'm unconvinced that that's caused by the language. I saw no evidence for that at all. As I'm pretty certain spectral analysis would show the two greens are far more similar than the blue and the green, there's something else going on there.


Why not? They're visually distinct, even in poor light.

Additionally, red and green are color opponents, as are blue and yellow. So, regardless of which triad you start at for prime colors, opponency theory has the answer for you.
Blue is opposed by orange and yellow by purple. This is easily verified by the colour of the afterimage you get after staring at a colour for a while.

[inky13112]

Why not? They're visually distinct, even in poor light.

Additionally, red and green are color opponents, as are blue and yellow. So, regardless of which triad you start at for prime colors, opponency theory has the answer for you.

I was always taught blue was opposed to orange. Purple is yellow's opposite

[Tyndmyr]

They are opponent colors in the human brain. The same neuron used to describe blue, in opposite format, describes yellow.

That is why yellowish-blue is not a color, and neither is reddish-green. Well, not generally, anyway. There's some rare cases in which you can see the two side by side and merge the two together, it's described as pretty unusual.

This is, incidentally, humorously referenced by Prachett in his description of Octarine.

[Asta Kask]

I wonder how cichlids would see this. They have five different genes for color-discrimination.

[Kneenibble]

They are opponent colors in the human brain. The same neuron used to describe blue, in opposite format, describes yellow.

That is why yellowish-blue is not a color, and neither is reddish-green. Well, not generally, anyway. There's some rare cases in which you can see the two side by side and merge the two together, it's described as pretty unusual.

This is, incidentally, humorously referenced by Prachett in his description of Octarine.

But that's because yellowish-blue is green, just like reddish-blue is purple and reddish-yellow is orange. Reddish-green is like to yellowish-purple or bluish-orange, not yellowish-blue. Heliomance mentioned that when you stare at something blue, the afterimage that hovers will be orange -- or at purple, something yellow. I don't understand the distinction you're trying to make.

[GrlumpTheElder]

Right, trust me on this, I'm a Vision Scientist


Depending on the colour system, green may also be a primary colour. And humans have receptor cells for green light.
Technically, any three combinations of colours can be primary colours as long as two of them cannot be used in any combination to make the third.



The normal human eye has Red, Blue and Green receptors. Which is the reason all monitors use RGB colors.
Some people also have a fourth kind for Yellow, which allows to see much starker differences in yellow shades. (I think all are women, since it's a recessive gene on the X chromosome.)
No.

There ARE three different receptors for colour (cones). Short wave (tuned to the 'blue' part of the spectrum), Medium Wave (tuned to the 'green' part of the spectrum) and Long wave (tuned to 'red'). Humans are Trichromats, meaning that we can see any colour with a combination of short wave, medium wave and longwave light.

No human ever has been Tetrachromatic (4 types of cones) Birds are, humans are not. However, if a person is deutranomal, their medium wave cones are tuned to slightly different wavelength, and may respond better to the 'yellow' than the 'green'


They are opponent colors in the human brain. The same neuron used to describe blue, in opposite format, describes yellow.

That is why yellowish-blue is not a color, and neither is reddish-green. Well, not generally, anyway. There's some rare cases in which you can see the two side by side and merge the two together, it's described as pretty unusual.

Almost. The same neuron used to describe 'blue' can also be used to descrine a combination of 'green' and 'red', resulting in 'yellow'. As I previously stated, there is no cone tuned to 'yellow'

Personally I think this might be the reason for these colours being used


Heliomance mentioned that when you stare at something blue, the afterimage that hovers will be orange -- or at purple, something yellow. I don't understand the distinction you're trying to make.
Depends on the shade of blue. One shade of blue will give you an after image of yellow, but if it's slightly red-y, the after effect will apear slightly different.

[Kneenibble]

Very interesting stuff. It explains why my budgie always criticizes my meticulously co-ordinated wardrobe.


Depends on the shade of blue. One shade of blue will give you an after image of yellow, but if it's slightly red-y, the after effect will apear slightly different.

I must disagree: my experiments drawing opposite-coloured flags, staring at them, and then looking at a white wall when I was 8 were very conclusive. :smalltongue:

[Surfing HalfOrc]

I can see the "cultural" color differences when it comes to my wife. She is Korean, and when the Stop Light changes, she always says the light is Blue.

I also know the joke where the wife shows her husband paint swatches of different shades of white:
Navajo
Eggshell
Linen
Dover
and the husband asks if the wife is just messing with him (as he only sees white).

As for the tetrachromats, I've read several articles that say some women have the gene. The article stated that a subject could identify subtle computer generated shades that a human could not.

Of course, the researcher went on to say: “Seeing 100 million colors is probably pretty mind boggling. Men probably could not handle it. That could be why it is restricted to women." Yeah, no research bias there...:smallsigh:

[Scorpina]

Not being clever, I have nothing clever to add, but I just wanted to say how interesting this thread is.

[willpell]

I think the thing of subtle color variations being a woman thing is just socialization. I can't be sure since I've never actually competed with a woman to see who can best disambiguate paint swatches or anything (that might make a neat concept for a game), but I easily identify at least hundreds of colors as being distinct, so I don't think the distinction can be biological.

[Erloas]

I can see the "cultural" color differences when it comes to my wife. She is Korean, and when the Stop Light changes, she always says the light is Blue. Do they use a different set of colors for their stop lights in Korea? (South I would assume) Or... depending how long she has been speaking whatever your natural language is (since it could very well not be English) is she just getting the word usage wrong?
I'm not aware of any colorblindness that is common between red and blue distinction.


I think the thing of subtle color variations being a woman thing is just socialization. I can't be sure since I've never actually competed with a woman to see who can best disambiguate paint swatches or anything (that might make a neat concept for a game), but I easily identify at least hundreds of colors as being distinct, so I don't think the distinction can be biological. There is some socialization in that a lot of people will see "white" and say it is "white" when they could clearly put 10 swatches together and see that they are all slightly different "whites". And when walking into a room they aren't going to care that this particular "white" is slightly more tan or slightly more blue or slightly more green then some other white because it is just white.

However there is also some biological aspects to color distinction. For instance color blindness much more common among men then women. A quick check on the internet shows about 20% of men have some form of colorblindness but only about 0.5% of women do. *Though I could be reading the numbers wrong as it is broken down kind of weird, either way it is clear that it is much more prevalent for men. There are also many different forms of colorblindness and many degrees of it.

And looking at the color blind tests on Wikipedia it seems I've got issues with the protanope type... I almost can't see the number, though it is very faintly visible.

[Serpentine]

In some places they do mix a bit of blue into the green traffic light to help colourblind people...
According to wikipedia, there's only 2 possible cases of human tetrachromats. I found a site some time ago that supposedly had a tetrachromacy test (similar to a colour blindness test), including an "if you can see the number here, please contact..." note on it. Unfortunately it seems the original site is gone, but I think this might be the test ('course, it could also be a fake):
http://128.111.69.4/~jevbratt/zoomorph_blog/assets/tetrachromat-color-test.jpg

My ex is colourblind. He can't tell the difference between green and orange, and between pink and blue. He insists he's "not that colourblind", that he "just can't tell between colours of a really close shade". I found it out when I was eating my dinner of carrots, peas, broccoli and brussels sprouts (or something like that), and he said "there's far too much orange on that plate". He thought the phrase "eat your greens" was meant ironically.

[Winter_Wolf]

I apparently have a minor blue-purple color deficiency. Minor, because I can still tell the difference most of the time, but I had a car which I am to this day convinced was purple, but everyone else says was dark blue.

That said I get a definite sense of a large 7 or small 26 in both the yellow and green circles, but the red just gives me eye strain. I'm probably just seeing dot patterns instead of actual numbers, though. I've always disliked color blindness tests and magic eye pictures.

[GrlumpTheElder]

That test is most likely a fake. The main reason I say that is because is because the colours on your computer screen are only being presented in three channels (RGB). Tetrachromatic birds usually extends out into the ultraviolet range of the EMS. Computer monitors are unable to render Electromagnetic radiation outside of the range of Visible light.

[Flickerdart]

That test is most likely a fake. The main reason I say that is because is because the colours on your computer screen are only being presented in three channels (RGB). Tetrachromatic birds usually extends out into the ultraviolet range of the EMS. Computer monitors are unable to render Electromagnetic radiation outside of the range of Visible light.
Tetrachromatic birds, sure, but human tetrachromats have an extra orange cone rather than a UV cone.

[Yora]

I apparently have a minor blue-purple color deficiency. Minor, because I can still tell the difference most of the time, but I had a car which I am to this day convinced was purple, but everyone else says was dark blue.
There is no purple!

Or at least, there are no purple wave lengths. What looks like purple is seeing both red and blue light at the same time. Telling the difference between blue and purple might actually be a problem with red. But in that case, you would be seeing red where there is none...

Or maybe, it's just a matter of your personal definition which shades are blue and which shades are purple, and you just happen to be an outlier among your group of friends.
I constantly get into short debated with my parents every time we see something turquoise about it being a bluish turquoise or a greenish turquoise.

:yuk: What color is this anyway? This is almost perfecly in balance.

In some places they do mix a bit of blue into the green traffic light to help colourblind people...
According to wikipedia, there's only 2 possible cases of human tetrachromats. I found a site some time ago that supposedly had a tetrachromacy test (similar to a colour blindness test), including an "if you can see the number here, please contact..." note on it. Unfortunately it seems the original site is gone, but I think this might be the test ('course, it could also be a fake):
http://128.111.69.4/~jevbratt/zoomorph_blog/assets/tetrachromat-color-test.jpg
I'd tried to put this through some filters and contrast changes in photoshop, but I never got it to detect any visible or nummerical differences. Though I don't really know how these things work and was just moving sliders at random.

This is the invisible pink unicorn, which as data is both defined as colored pink, but also as 100% transparent.

>http://upload.wikimedia.org/wikipedia/commons/d/d5/Ipu.png<

[Surfing HalfOrc]

Do they use a different set of colors for their stop lights in Korea? (South I would assume) Or... depending how long she has been speaking whatever your natural language is (since it could very well not be English) is she just getting the word usage wrong?
I'm not aware of any colorblindness that is common between red and blue distinction.


No, Korea uses (to me) the exact same shade of red/yellow/green as we do in the U.S. My wife emigrated to the U.S. when she was 11, so she speaks fluent, colloquial English. And she definitely knows the difference between a blue and green poker chip!
Blue=10
Green=25

She has lived in the U.S. (mostly Hawaii) for 30+ years, and we have been married for 21 years. She just says "The light is blue" if I'm not paying attention when stopped.

[Yora]

Japanese introduced a clearly seperate term for green centuries ago, but some things are are still called "aoi", even though in the color spectrum, they are clearly in the region of "midori". Like apples and traffic lights.

[Siosilvar]

Do they use a different set of colors for their stop lights in Korea? (South I would assume) Or... depending how long she has been speaking whatever your natural language is (since it could very well not be English) is she just getting the word usage wrong?
I'm not aware of any colorblindness that is common between red and blue distinction.

IIRC, the word for "blue" and "green" in Korean is the same word, so she probably doesn't notice the distinction unless she makes a conscious effort to.

I watched a video where they tested this with an African tribe. They displayed a circle of 12 colored squares on a screen, with one different from the rest. In the first case, there was a very obviously (to me) blue square in a ring of green. The second case had a slightly yellow green in a ring of lime green. The tribe members, with a word to distinguish between yellow-green and lime green but just one for lime green and blue, spent much longer on the first test and very quickly pointed out the second one, which was the opposite the results of English speakers who took the test.

[Heliomance]

The video was linked earlier :P

[Winter_Wolf]

There is no purple!

Or at least, there are no purple wave lengths. What looks like purple is seeing both red and blue light at the same time. Telling the difference between blue and purple might actually be a problem with red. But in that case, you would be seeing red where there is none...


Or it could be that the car was coated in pearl-coat paint. It did look strikingly different in direct sunlight and overcast days.

I also have a weird thing where one eye sees reds more, and the other eye sees blue more. No one else seems to know what I'm talking about, though. I used to test this repeatedly during fishing season while waiting pick the nets. Yeah, mostly drift-netting is NOT a high adrenaline pursuit, just a lot of hurry up and wait. Anyway! The radar cover was blue, and I'd sit up on the flying bridge and close one eye, then switch to the other, and it was consistent.

I was later diagnosed with macular degeneration (http://en.wikipedia.org/wiki/Macular_Degeneration) in one eye, so it's also entirely possible that I've been looking at the world through a layer of blood (in one eye).

Also, purple is as real as spoons. :smalltongue:

[Ravens_cry]

I have a theory we are so sensitive to different greens because we are omnivores.
A slight shade difference in the colour of leaves could mean the difference between dandy dinner and doomful death.

[Elemental]

I have a theory we are so sensitive to different greens because we are omnivores.
A slight shade difference in the colour of leaves could mean the difference between dandy dinner and doomful death.

That would explain why some cultures have more words for various greens and almost none for blue.
After all... Blue isn't a very commonly found colour in nature...
Except for the sky, but when you're looking for stuff to eat, unless you're a good shot with a bow, there's not much point looking up.

[Ravens_cry]

That would explain why some cultures have more words for various greens and almost none for blue.
After all... Blue isn't a very commonly found colour in nature...
Except for the sky, but when you're looking for stuff to eat, unless you're a good shot with a bow, there's not much point looking up.
And bows are a fairly recent invention, evolutionarily speaking.

[Mono Vertigo]

I feel this (http://blog.xkcd.com/2010/05/03/color-survey-results/) is relevant to the discussion.
(WARNING: swears and general immaturity behind the link.)

[Erloas]

I have a theory we are so sensitive to different greens because we are omnivores.
A slight shade difference in the colour of leaves could mean the difference between dandy dinner and doomful death.

I don't think there are any correlation between color and eatability in plants. As it is there is a huge range of greens in plants that we do eat. I think the majority of plant based problems is also the berry rather then the greens and most berries are not green.

One big reason for green being easier to distinguish is the fact that it simply takes up more space on the visual spectrum.
{table]Color| Frequency |Wavelength |range
violet |668–789 THz| 380–450 nm |70
blue |606–668 THz| 450–495 nm |45
green |526–606 THz| 495–570 nm |75
yellow| 508–526 THz| 570–590 nm |20
orange |484–508 THz| 590–620 nm |30
red| 400–484 THz| 620–750 nm |130[/table]
So green is the second longest section, but both red and violet are at the ends of the visible spectrum so some extent of that range it outside of what people can see.

[Ravens_cry]

I don't think there are any correlation between color and eatability in plants. As it is there is a huge range of greens in plants that we do eat. I think the majority of plant based problems is also the berry rather then the greens and most berries are not green.

No, but it can help you identify one plant from another, especially in the non-fruit seasons.

[Elemental]

No, but it can help you identify one plant from another, especially in the non-fruit seasons.

Indeed. And very few plants are constantly in flower or in fruit.
If they were, then identifying them would be easy.

Otherwise, you need to go by leaf shape, which is often very similar from plant to plant.
And echoing what Ravens_Cry said earlier, a slight variation in shade means the difference between salad and food poisoning. Foxglove, for instance, can be easily mistaken for other plants.

[Erloas]

Otherwise, you need to go by leaf shape, which is often very similar from plant to plant.
And echoing what Ravens_Cry said earlier, a slight variation in shade means the difference between salad and food poisoning. Foxglove, for instance, can be easily mistaken for other plants.
But there are a lot of plants that have different coloring depending on the time of year or how much water or sun they have. You can get one plant that has different coloration on different leaves at the same time. Some plants are very consistently colored, others are not.

And if we take a plant like a maple tree, they have very distinctive leaf shapes but they come in all sorts of different colors, with greens, reds, and silvers being very common.

[Elemental]

But there are a lot of plants that have different coloring depending on the time of year or how much water or sun they have. You can get one plant that has different coloration on different leaves at the same time. Some plants are very consistently colored, others are not.

And if we take a plant like a maple tree, they have very distinctive leaf shapes but they come in all sorts of different colors, with greens, reds, and silvers being very common.

The main difference being that humans don't eat maple leaves, but they eat the leaves of numerous smaller plants.
But, there are a lot of examples of plants that are highly toxic that bear striking similarities to other plants that are rather good to eat, and leaf shape can't always be relied upon.
Foxglove, for instance, looks rather similar to comfrey and sage and poison hemlock resembles wild carrot and wild parsnip.

[Devils_Advocate]

There's a Wikipedia article on the Opponent Process Color Theory (http://en.wikipedia.org/wiki/Opponent_process), which describes what's meant by "opponent colors" in that context.

Language can definitely mess with your perception of color. I wasn't even aware until recently that brown is dark orange... but I imagine that I would have been if English didn't have "brown" as a basic color term!

As another example of this: Do a Google image search for "traffic light". See how the "go" light is typically a lot bluer in the photos than in the drawings? That's because those drawings were made by people who were taught that traffic lights are "green"! O_O The "go" color on most traffic lights is actually more of a cyan that it seems pretty reasonable to call "blue" when I consider it closely. But I never did consider it closely until it was brought to my attention... and thus the way that that color is commonly refered to by English speakers greatly influenced my perception of it.


The case was clearly made that they can tell the greens apart far better than the green and the blue, but I'm unconvinced that that's caused by the language. I saw no evidence for that at all. As I'm pretty certain spectral analysis would show the two greens are far more similar than the blue and the green, there's something else going on there.
... That doesn't make any sense. If someone can more readily distinguish two colors that she has different terms for from each other than she can distinguish two colors that she uses the same term for from each other, despite the differently-termed colors being more similar to each other than the same-termed colors, surely that's evidence in support of the theory that having different terms for colors makes them easier to distinguish! It's the exact opposite of an indication that "there's something else going on there". :smallconfused:


Magenta isn't even a spectral colour but a fraud
What about being non-spectral makes magenta fraudulent?


What makes CMY any more valid than RYB?
The former can be combined to produce more colors than the latter. You can make red by mixing magenta and yellow; and you can make blue by mixing cyan and magenta; but you can't get cyan nor magenta by mixing red, yellow, and/or blue. So RYB allows you to produce only a subset of the colors that you can produce with CMY. I think.


On the topic of color geekery, I've always kind of rolled my eyes at the idea that the rainbow includes Indigo
"A careful reading of Newton's work indicates that the color he called indigo (http://en.wikipedia.org/wiki/Indigo), we would normally call blue; his blue is then what we would name blue-green or cyan."
- Gary Waldman

The color termed "blue" in the RGB model looks a bit violet to me. And judging by the xkcd color survey results (http://blog.xkcd.com/2010/05/03/color-survey-results/), people more commonly think of blue as being less violet than that. I've taken to thinking of RGB blue as "indigo blue"; it's helpful to have a more specific term for it, since "blue" is really a much broader basic color term.


I've semi-recently come to the conclusion that I consider Gold to be a distinct color between Orange and Yellow. The rainbow doesn't agree with me, but I'm not one for taking my cue from nature anyway. So for my purposes, there are eight primary and secondary colors.
Which colors are they?


:yuk: What color is this anyway? This is almost perfecly in balance.
"Teal" is the word for dark cyan.


Do they use a different set of colors for their stop lights in Korea? (South I would assume) Or... depending how long she has been speaking whatever your natural language is (since it could very well not be English) is she just getting the word usage wrong?
I'm not aware of any colorblindness that is common between red and blue distinction.
I'm pretty sure that Surfing HalfOrc meant "when the light changes from 'stop' to 'go'", not "when the light changes to 'stop'".


IIRC, the word for "blue" and "green" in Korean is the same word, so she probably doesn't notice the distinction unless she makes a conscious effort to.
What you mean, I think, is that Korean has a basic color term that covers colors that English-speakers call "blue" and colors that English-speakers call "green". Describing this state of affairs by saying that Korean uses the same word for green and blue is misleading at best, like saying that the English word for azure is "blue". It's not English lacks the narrower term, it's that the narrower term isn't commonly used and the distinction between different hues of "blue" isn't commonly drawn -- despite the fact that they're readily distinguishable from each other even by someone whose language doesn't include different basic color terms for them!

[Heliomance]

... That doesn't make any sense. If someone can more readily distinguish two colors that she has different terms for from each other than she can distinguish two colors that she uses the same term for from each other, despite the differently-termed colors being more similar to each other than the same-termed colors, surely that's evidence in support of the theory that having different terms for colors makes them easier to distinguish! It's the exact opposite of an indication that "there's something else going on there". :smallconfused:


Correlation does not imply causation. And even when causation is there, we must establish which is cause and which is effect. Personally, I think it far more likely that they have different words for the shades of green because they appear as different colours to them, rather than the other way around.

[Rising Phoenix]

I wonder how cichlids would see this. They have five different genes for color-discrimination.

Mantis shrimp have 14+ colour receptors in their eyes... their view of the world must be... spectacular...

[ThiagoMartell]

Very interesting thread.

[Iruka]

Correlation does not imply causation. And even when causation is there, we must establish which is cause and which is effect. Personally, I think it far more likely that they have different words for the shades of green because they appear as different colours to them, rather than the other way around.

Clearly we should kidnap their children before they start to speak, teach them English and have them identify colours for us. For science!

I find it more likely that their colour perception is influenced by language then them having a random genetic mutation that changes their perception of green. But that's mostly a gut feeling on my side. I'm sure I've read about other studies about that topic, but I can't remember where.

Here's a study (http://www.rochester.edu/news/show.php?id=2299) that claims the number of color-sensitive cones doesn't affect how you perceive colours.

There's even a long wikipedia article (en.wikipedia.org/wiki/Linguistic_relativity_and_the_color_naming_debate) about this debate. Fascinating. :smallbiggrin:

[John Cribati]

This thread is making me question my literal worldview.

[Heliomance]

I'm pretty sure there have been studies done on whether language influences culture (in the popular "they have no word for peace" fashion), and found little evidence to support the idea. I can't remember what to search for to find the results again though, I'm afraid.

[Surfing HalfOrc]

Very interesting thread.

It is! I was actually only wondering why game makers chose those four colors most commonly for pawns, especially for "children's" games. Especially since the first games I remember tended to have either red and black pieces (checkers) or white and black pieces (chess).

There is a certain "cheerfulness" to RBYG, which seemed absent from R/B or W/B game sets.

Sorry! had white pawns (I think? It's been over 40 years since I last played) in addition to blue, green and red, while Monopoly had silver pawns, and multi-colored money. (I saw an image showing how modern U.S. currency matches the Monopoly color scheme:smallamused:).

[Devils_Advocate]

The "go" color on most traffic lights is actually more of a cyan that it seems pretty reasonable to call "blue" when I consider it closely.
For that matter, the "yellow" light is really orange or at least orange-yellow in the vast majority of cases. But it's usually drawn that way too, so I guess that people are more aware of that. (Pure yellow is pretty distinct, at least to me.)


you can make blue by mixing cyan and yellow
For the record, I never said this. Why would I have said this? Especially in the same post in which I mention that "indigo blue" (as I termed it) looks rather violet to me, as if it weren't already plain enough that green is what you get by mixing cyan and yellow. So obviously I never said it.


Correlation does not imply causation. And even when causation is there, we must establish which is cause and which is effect.
Hmm. OK, true. But that video doesn't appear to support any particular causal explanation over any other. Which I guess means we were both wrong?


Personally, I think it far more likely that they have different words for the shades of green because they appear as different colours to them, rather than the other way around.
Those possibilities are hardly mutually exclusive!

But if I understand you right, you're saying that you already had your mind largely made up on this issue, and that you were interpreting what you saw under the unspoken assumption that the influence of language on color perception is minor.

If so, that's why I had a hard time understanding you. It hadn't really occurred to me that someone might assume that. ... Why would you assume that?

For that matter, why are you "pretty certain spectral analysis would show the two greens are far more similar than the blue and the green"? Obviously, it doesn't make sense to say that just because the two greens look more similar to each other to you; you have no reason to assume that your own subjective perception of color more closely matches objective reality. Furthermore, I'm not sure that there's an unbiased measure of "similarity" in this context.

My understanding is that humans start out with perceptual superpowers in infancy (http://www.cracked.com/article_18538_5-superpowers-we-all-had-as-babies-according-to-science.html), able to distinguish far more colors, faces, sounds, etc. than adults. But then synaptic pruning (http://en.wikipedia.org/wiki/Synaptic_pruning) or something happens to bias us towards making only "relevant" distinctions -- to the point that we lose much of our ability to make other distinctions!


Clearly we should kidnap their children before they start to speak, teach them English and have them identify colours for us. For science!
But in order to control for everything but language, you'd have to keep every other aspect of their environment the same, and language may be interrelated with other aspects of their environment in ways that make this impossible even in principle, never mind in practice. It would probably be necessary to run several different tests on several large groups in order to control for different variables separately.

Teaching the Himba language to children in English-speaking countries would almost certainly be the easier approach.


I'm pretty sure there have been studies done on whether language influences culture (in the popular "they have no word for peace" fashion), and found little evidence to support the idea. I can't remember what to search for to find the results again though, I'm afraid.
Wikipedia article! (http://en.wikipedia.org/wiki/Linguistic_relativity)


I was actually only wondering why game makers chose those four colors most commonly for pawns, especially for "children's" games.
It seems that those are the four most "basic" colors (http://en.wikipedia.org/wiki/Color_term#Basic_color_terms) other than white and black. They're probably chosen as both primary colors and game piece colors for that reason (though the designation of a color as "primary" undoubtedly reinforces its status as "basic").

Were I picking out four colors meant to be as distinct from each other as possible, I'd probably go with white, black, red, and green. But in many cases you're working with a black and white background and want colors to stand out well against that background. In that context, red, yellow, green, and blue make the most sense. And of course non-neutral colors are more vibrant -- more "cheerful" as you put it.


Sorry! had white pawns (I think? It's been over 40 years since I last played) in addition to blue, green and red
A Google image search shows that Sorry! uses the RYGB model. Google seems to be pretty good for quickly checking what something looks like.

Also, it apparently lets you filter images by color, which I never really noticed before. Specifically, you can choose Full Color, Black & White, or... any of the 12 "basic" colors, including the one that English lacks a basic color term for ("teal", here).

Pretty nifty!

[Heliomance]

But if I understand you right, you're saying that you already had your mind largely made up on this issue, and that you were interpreting what you saw under the unspoken assumption that the influence of language on color perception is minor.

If so, that's why I had a hard time understanding you. It hadn't really occurred to me that someone might assume that. ... Why would you assume that?
In that I think it more likely that a genetically insular group of people have a mutation that causes them to perceive the world differently than that their language does, then yes. I saw the situation, I developed a hypothesis. It is different from your hypothesis, but that doesn't matter. If I cared enough and had the resources, the next step would be to design an experiment that would show which (if either) of the hypotheses is best supported by reality. I do not care enough, nor do I have the resources :P


For that matter, why are you "pretty certain spectral analysis would show the two greens are far more similar than the blue and the green"? Obviously, it doesn't make sense to say that just because the two greens look more similar to each other to you; you have no reason to assume that your own subjective perception of color more closely matches objective reality. Furthermore, I'm not sure that there's an unbiased measure of "similarity" in this context.
There's a very easy measure - wavelength of the light reflected by the pigments in question. I strongly suspect that the two shades of green will be closer in wavelength than the green and the blue, though I am willing to be proved wrong on that count.

[grimbold]

...that can be perceived by most humans.

mind=blown

ironic that it's been done by Logic :P

[Devils_Advocate]

I think it more likely that a genetically insular group of people have a mutation that causes them to perceive the world differently than that their language does
Why? To be frank, your intuition hardly counts as evidence unless you have good reason to believe that your intuition is particularly good. You do understand this principle, I hope!

I gather that it has been pretty well-established that environmental factors influence perception, and in particular which distinctions we remain capable of making after our early development. And without evidence that a known environmental factor is insufficient to account for an observed difference, there's no good reason to posit an additional genetic factor. Occam's Razor, man!

Yes, there's still the question of what caused the language differences in the first place. But if we're positing random changes spreading through a population either way, I see no reason to suppose that the differences were in genotype rather than in vocabulary.


There's a very easy measure - wavelength of the light reflected by the pigments in question.
What makes wavelength a better measure of similarity than e.g. frequency?

A larger difference in wavelength may correspond to a smaller difference in frequency; consider the ranges for violet and red light in Erloas's post (http://www.giantitp.com/forums/showthread.php?p=13812995#post13812995), for example.


I strongly suspect that the two shades of green will be closer in wavelength than the green and the blue
Why? Doesn't it seem most likely that the experimenters would choose colors with an equal difference between them, so as to control for that factor?

[Heliomance]

Why? To be frank, your intuition hardly counts as evidence unless you have good reason to believe that your intuition is particularly good. You do understand this principle, I hope!

Oh, naturally, yes. But the same holds true for you. I have seen no solid evidence either way on the matter, apart from vaguely remembered studies suggesting that language doesn't influence culture all that much.


I gather that it has been pretty well-established that environmental factors influence perception, and in particular which distinctions we remain capable of making after our early development. And without evidence that a known environmental factor is insufficient to account for an observed difference, there's no good reason to posit an additional genetic factor. Occam's Razor, man!

I see no reason why the theory that the language difference caused the perception difference is any better.



What makes wavelength a better measure of similarity than e.g. frequency?

A larger difference in wavelength may correspond to a smaller difference in frequency; consider the ranges for violet and red light in Erloas's post (http://www.giantitp.com/forums/showthread.php?p=13812995#post13812995), for example.
As the speed of light is constant, frequency and wavelength are directly relatable. Wavelength = speed of light/frequency, so the two measures are equally valid and will produce identical results.



Why? Doesn't it seem most likely that the experimenters would choose colors with an equal difference between them, so as to control for that factor?

Did they? They didn't say they did. Again, we have no evidence either way, unless you care to replay the video and analyse the colours shown. I did say I was willing to be proved wrong. I know I don't care enough to do the analysis myself, though.

[willpell]

Occam's Razor, man!

seethes intensely but holds his tongue

[Iruka]

Here are some more details about the Himba study:

http://www.apa.org/monitor/feb05/hues.aspx

The publication is unfortunately not accessible without purchase.

[Heliomance]

seethes intensely but holds his tongue

...that's self-evidently not holding your tongue.

[willpell]

It was in italics so it describes an action rather than signifying digital "speech".

[Tvtyrant]

This thread is a little long to read all the way through, but there was a book that analyzed the Homeric epics and came to the conclusion that the ancient Greeks had not yet begun to distinguish between colors. Instead the book posits that they concentrated on intensity, using examples like a comparison of iron and cows to show something dull.

[Ravens_cry]

That sounds frankly absurd given the mention of colour in contemporary and older works.
The language of the time may have lacked specific words, but even English doesn't name *all* the colours.

[Heliomance]

It was in italics so it describes an action rather than signifying digital "speech".

Yes, but you didn't need to say anything at all. Commenting to say you're not going to comment is inherently pointless.

[willpell]

Yes, but you didn't need to say anything at all. Commenting to say you're not going to comment is inherently pointless.

I was commenting to say that I wasn't going to launch into a rant about what a BS idea Occam's Razor is. Which is less pointless, though still largely so, given how uniformly people other than me accept it as the easy excuse which it is. And I'm going to stop myself now because I get carried away way too easily talking about this.

[Heliomance]

I was commenting to say that I wasn't going to launch into a rant about what a BS idea Occam's Razor is. Which is less pointless, though still largely so, given how uniformly people other than me accept it as the easy excuse which it is. And I'm going to stop myself now because I get carried away way too easily talking about this.

Why bother? If you're going to restrain yourself from launching into a rant, why do other people need to know about your restraint? Why say anything at all?

[Trog]

*skims thread* Right. I'll respond with...

This. (http://en.wikipedia.org/wiki/Opponent_process)

[Devils_Advocate]

Oh, naturally, yes. But the same holds true for you. I have seen no solid evidence either way on the matter,
So without much evidence either way, neither of us should regard either possibility as much more probable than the other, right?


apart from vaguely remembered studies suggesting that language doesn't influence culture all that much.
This hardly seems like a big cultural difference to me. It wouldn't even have occurred to me to call it "cultural", really.


I see no reason why the theory that the language difference caused the perception difference is any better.
Well, it's just that language has a tendency to influence perception in general. Consider gendered nouns (http://www.qwantz.com/index.php?comic=1917), for example. (Note: I going out on a limb here and implying that German bridges are not in fact generally daintier than Spanish bridges. If you can demonstrate that they are then I am SO BUSTED.)


As the speed of light is constant, frequency and wavelength are directly relatable.
This is true.


Wavelength = speed of light/frequency, so the two measures are equally valid and will produce identical results.
NO. X - Y is not directly proportional to c/X - c/Y; you cannot multiply one of those expression by a constant to get the other. As I said, you can even see this in Erloas's graph. Violet light covers a larger range of frequencies than red light but a smaller range of wavelengths.


we have no evidence either way
Well then you shouldn't "strongly suspect" one way or the other now should you? ;)


I was commenting to say that I wasn't going to launch into a rant about what a BS idea Occam's Razor is. Which is less pointless, though still largely so, given how uniformly people other than me accept it as the easy excuse which it is.
The principle of parsimony isn't B.S. or an excuse, just commonly misunderstood (http://lesswrong.com/lw/jp/occams_razor/). In fact I'm not completely certain that I didn't misapply it here. I'd urge you not to judge the principle by the sort of things that it's commonly ostensibly invoked to support.

The relevant idea is that all else being equal, the larger of two sets of assumptions is more likely to contain an incorrect assumption. (See also the conjunction fallacy (http://en.wikipedia.org/wiki/Conjunction_fallacy).) This is rather like how an entire book is more likely to contain a typo than a single sentence, all else being equal. That much seems fairly obvious, doesn't it?

[Sutremaine]

It was in italics so it describes an action rather than signifying digital "speech".
Doesn't matter, you posted it anyway.

[Heliomance]

This hardly seems like a big cultural difference to me. It wouldn't even have occurred to me to call it "cultural", really.
What else would you call it? Seems pretty cultural to me.



Well, it's just that language has a tendency to influence perception in general. Consider gendered nouns (http://www.qwantz.com/index.php?comic=1917), for example. (Note: I going out on a limb here and implying that German bridges are not in fact generally daintier than Spanish bridges. If you can demonstrate that they are then I am SO BUSTED.)
That I did not know, and it's fascinating. I am tempted to drop a [citation needed] on you though.



NO. X - Y is not directly proportional to c/X - c/Y; you cannot multiply one of those expression by a constant to get the other. As I said, you can even see this in Erloas's graph. Violet light covers a larger range of frequencies than red light but a smaller range of wavelengths.
Eh, that's correctable for. The point is not an important one - the point is that, whether we decide to use frequency or wavelength, we do have a quantitative way to describe colour.



Well then you shouldn't "strongly suspect" one way or the other now should you? ;)

I'm human, I'm allowed to suspect whatever I want to suspect. That's what a hypothesis is. It remains a hypothesis until either disproved or sufficient supporting evidence is obtained.

[Kd7sov]

That sounds frankly absurd given the mention of colour in contemporary and older works.
The language of the time may have lacked specific words, but even English doesn't name *all* the colours.

Possibly relevant (or possibly not...), I recall my dad talking recently about something he'd read or heard in a podcast or something, about most languages first naming colors in about the same order - so that, for instance, a word for "red" would usually be first, or almost first, and a word for "blue" would usually be last or almost last. I don't remember if that's what he remembered his source citing as the usual first and last, but it illustrates the concept.

[Logic]

mind=blown

ironic that it's been done by Logic :P

Glad to be of service!

[Leon]

Since red paint is basically "anti-blue" and "anti-green" mixed together, and green is "anti-red" and "anti-blue", that makes sense. Paints are subtractive, i.e. they don't work by emitting light (which would be silly), but by not reflecting certain colors.

Does Anti- Matter?

[willpell]

Paints are subtractive, i.e. they don't work by emitting light (which would be silly)

Silly heck, I'd pay good money for luminous color paint that you could use to create instant vanity flashlights at a rave or something.

[Ravens_cry]

Possibly relevant (or possibly not...), I recall my dad talking recently about something he'd read or heard in a podcast or something, about most languages first naming colors in about the same order - so that, for instance, a word for "red" would usually be first, or almost first, and a word for "blue" would usually be last or almost last. I don't remember if that's what he remembered his source citing as the usual first and last, but it illustrates the concept.
I wonder why red, assuming that's true. Blue I can understand, little is blue that is worth mentioning. The sky, the most commonly blue thing, can also be described as 'clear' or 'not cloudy'.

[Elemental]

I wonder why red, assuming that's true. Blue I can understand, little is blue that is worth mentioning. The sky, the most commonly blue thing, can also be described as 'clear' or 'not cloudy'.

Red is a very distinct colour, as is blue. But unlike blue, more things that are important to us are coloured red.
Blood, for instance. Numerous vegetables and flowers, the leaves of trees in Autumn, the Sun as it sets, the meat of many animals, certain soils, iron ore, rust...
In comparison, blue doesn't show up as much in nature. Sure, there are blue flowers and berries, and some birds have blue feathers, but they're a comparative minority.

[Ashtagon]

http://en.wikipedia.org/wiki/Color_term#Basic_color_terms

This is why. It makes things easier for humans to understand at a primeval level.

After black and white, those four colours are the most basic colour concepts that exist in human language, which reduces the amount of hindbrain work in processing the information.

[Watcher]

I always figured it was primary colors (in the elementary school color wheel sense) which are happy-looking generally and green because it doesn't clash with the others. Orange would make too many warm colors and purple would stick out against yellow too much and possibly blend in too well with blue. With green, though, it doesn't oppose red too strongly and doesn't look like, blue, yellow, or any kind of mixture that you can easily and immediately imagine.

Also, it's getting weirdly heated for a debate about colors.

EDIT: Whoah, I looked at the stoplight photos, and they all do seem to be bluish instead of green! It could be like how embers look purple through some cameras but red to people looking at them. I'll look at the stoplights on my way to the city tomorrow.

EDIT 2: Nopers. All of the stoplights are completely green. Some of the green arrows have a hint of bluish in them, but there aren't any blue or even tealish lights. Maybe it's the cameras. Maybe other places have blue lights and there just aren't any in this city.

[sktarq]

I also know the joke where the wife shows her husband paint swatches of different shades of white:
Navajo
Eggshell
Linen
Dover
and the husband asks if the wife is just messing with him (as he only sees white).

And this is totally training. I went to a high school with a museum of paleontology on campus. White sand stone was just a white sand stone when I started but by the time I left it was a dozen microshade. And if you look at the field notes of most paleontologist to describe how to find the exact point where the fossil was removed the descriptions include blues, greens, purples, oranges, umber etc o- all to describe a mass of stone that most people would call grey. That adjusted vision is still with me today. But only with plants and earth materials.

EDIT: Grump: I remember from my Psych 101 book that they described a tetrachrome as the basic human eye with two kinds of cone one that was responsible for red (with a positive reaction) and green (with a negative reaction-or impeeded reaction I forget the exact term in the last 13 years) and a second type of cone with a blue (with a positive reaction) and a yellow (the opposite). Red Green colour blindness was due a failure in the first type of cone. They also presented the yellow reaction as being rather new to science. Why was it presented in this way? A book that thought that psych 101 students couldn't get it? was it thought that this was true for a few years in the late 90's?

[Ashtagon]

Actually, here's something.

For my own purposes, I did a colour wheel thingy for a private wiki, and discovered some stuff about my own colour perception in the process.

My eyes are very sensitive to hue changes in the red-yellow end of the colour wheel, so much so that I added an extra segment of colours into my code because otherwise the gap would have been jarring for me. On the other hand, around the green to blue range of the spectrum, I have a hard time distinguishing subtle changes in luminosity.

Is this the general experience, or are my eyes special in some way?

[Ravens_cry]

Not sure, I've never tried it, but I have noticed things look a little bluer with my right eye compared to my left.

[Mauve Shirt]

I always thought they should take ugly yellow out of the crayon box and add more purple. :smallcool:

[Asta Kask]

There's a very easy measure - wavelength of the light reflected by the pigments in question. I strongly suspect that the two shades of green will be closer in wavelength than the green and the blue, though I am willing to be proved wrong on that count.

There's not a one-to-one correspondence between color and wavelength (or frequency), because the human brain processes all pictures that come in. The color of a given patch will depend not only on frequency/wavelength but also on context - the surroundings.

http://web.mit.edu/persci/people/adelson/images/checkershadow/checkershadow_double_med.jpg

Squares A and B are the same shade of gray, but the human brain adjusts automatically.

[Flickerdart]

And this is totally training. I went to a high school with a museum of paleontology on campus. White sand stone was just a white sand stone when I started but by the time I left it was a dozen microshade. And if you look at the field notes of most paleontologist to describe how to find the exact point where the fossil was removed the descriptions include blues, greens, purples, oranges, umber etc o- all to describe a mass of stone that most people would call grey. That adjusted vision is still with me today. But only with plants and earth materials.


That sounds exactly like stonecunning.

[Elemental]

I always thought they should take ugly yellow out of the crayon box and add more purple. :smallcool:

I am in complete agreement with you concerning this. With all the space wasted on the colours that aren't nice, they could add more nice colours!

[Heliomance]

True, that's a factor I hadn't taken into account. I don't imagine that effect would come into play with the color circles they were using, though.

[Wardog]

Another thing to consider: how we name colours depends on context.

"White" people are usually pink or pinky-brown.
"White" grapes are green.
"White" wine is greeny-yellow.


Also, how we percieve colour also depends on what other colours and shades we see with them, as in this optical illusion:
http://www.popularscience.co.uk/?p=1478
http://www.popularscience.co.uk/features/checkershadow-AB.jpg

[Mauve Shirt]

"White" people are usually pink or pinky-brown.


Unless they play minecraft and/or work in a basement and/or are Scandinavian. Then they're so white they're practically luminescent! :smalltongue:

[GrlumpTheElder]

Grlump: I remember from MY Psych 101 book that they described a tetrachrome as the basic human eye with two kinds of cone one that was responsible for red (with a positive reaction) and green (with a negative reaction-or impeeded reaction I forget the exact term in the last 13 years) and a second type of cone with a blue (with a positive reaction) and a yellow (the opposite).
I think you meant two cone systems rather than just cones (see Trog's link to Opponent Coding Processes). Opponent Process is the reason we can't perceive a reddish-green or a blueish-yellow. To account for the opponent-appearance of colours there are two chromatic (red-green and blue-yellow) opponent systems and one achromatic (black-white) opponent system.The first stage of colour vision is trichromatic (involving three types of detectors at the photoreceptor stage) and the second stage involves these three opponent processes.
The image below should help:

http://www.visualexpert.com/sbfaqimages/RGBOpponent.gif
From http://www.visualexpert.com/

As a key, L stands for Long Wavelenth Light, or red. M stands for Medium Wavelength, or green. S stands for Short Wavelength, or blue.

Ignore the first system.
If the eye is exposed to red light for a period of time, the red receptor (L) will become fatigued. Then, if white light is presented, the white light will appear green.

As there is no receptor for yellow, it is substituted with a red/green system. The same applies. If the eye is exposed to blue light for a period of time, the blue receptor (S) will become fatigued. Then, if white light is presented, the white light will appear yellow.


Red Green colour blindness was due a failure in the first type of cone. They also presented the yellow reaction as being rather new to science. Why was it presented in this way? A book that thought that psych 101 students couldn't get it? was it thought that this was true for a few years in the late 90's?
There are many different types of colour deficiency (only one true type of colour blindness). By Red/Green colour blindness, you can either mean Dichromacy or Anomalous trichromacy. Dichromacy is when you are missing a certain cone (protanopia is the lack of a L cone (red) and deuteranopia is lack of a M cone (green)). Anomalous trichromacy is when the sensitivity of a certain cone is not at usual parameters (protanomaly is when the L cone is shifted towards the M cone and deuteranomaly is when the M cone is shifted towards the M cone.)

In the 90s there were a lot of new theories presented as fact that have now been disproved.


Not sure, I've never tried it, but I have noticed things look a little bluer with MY right eye compared to MY left.
The main reason this happens is that one eye is slightly adapted to certain wavelengths of light. In the average situation, you're not getting exactly the same light in both eyes. As with above, it's possible that when you noticed this, the light entering your right eye had been more yellow, fatiguing the R/G system in that eye and causing white light to appear bluer. It's not permanent though. I had the same thing happen to me quite a lot, because of where MY window was in MY room. One eye got different light levels, resulting in the different appearances of a white surface...

I think that's everything.

tl:dr
The neural system of vision is funky!

[WalkingTarget]

This thread is a little long to read all the way through, but there was a book that analyzed the Homeric epics and came to the conclusion that the ancient Greeks had not yet begun to distinguish between colors. Instead the book posits that they concentrated on intensity, using examples like a comparison of iron and cows to show something dull.

William Gladstone, on-again off-again British Prime Minister, advanced a theory in the 1850's that Greeks of Homer's time (and I think people in general using Homer's text as just a source text) hadn't developed/were only then developing color vision due to the things you point out. That's pretty much discounted these days, more accepting that they simply had grouped colors by intensity/saturation rather than specific frequencies.

Guy Deutscher's Through the Language Glass discusses this and other color/thought-process/perception crossovers. I found it interesting. One of my favorite bits was how the language that was the source of the word "kangaroo" has no relative directional words (left, right, front, behind, etc.) - they use the equivalent of cardinal directions for everything.

[sktarq]

I think you meant two cone systems rather than just cones (see Trog's link to Opponent Coding Processes). ...In the 90s there were a lot of new theories presented as fact that have now been disproved.
...I think that's everything...The neural system of vision are funky!
Thanx it seems like some sort of version of this is what they were trying to get accross. Though they did not present it a cone systems. (They had a picture of two cones on the movie screen-one for red/green and one for blue/yellow) I'm going to put that down to it being a psych class not anatomy or vision science. Thank you for that explination.

[nedz]

That sounds frankly absurd given the mention of colour in contemporary and older works.
The language of the time may have lacked specific words, but even English doesn't name *all* the colours.

Pink (http://en.wikipedia.org/wiki/Pink) wasn't named until the 17th Century, and even then it was yellow.


Silly heck, I'd pay good money for luminous color paint that you could use to create instant vanity flashlights at a rave or something.

Glowstick, Snip, Paint.
Its a little bit toxic though.

[Devils_Advocate]

What else would you call it? Seems pretty cultural to me.
"Individual capability", I guess? I think of the word "culture" as referring to how people interact with each other. By which standard the language difference itself is the cultural element, and color discrimination is the related not inherently cultural thingy.


That I did not know, and it's fascinating. I am tempted to drop a [citation needed] on you though.
There's a link to a relevant paper (http://www-psych.stanford.edu/~lera/papers/gender.pdf) underneath the comic. Though I haven't read it myself.

(Dinosaur Comics! Where dinosaurs discuss linguistics (http://www.qwantz.com/index.php?comic=2129), complete with references! Sometimes!)


Eh, that's correctable for.
How? What would it even mean to "correct for" this?


The point is not an important one - the point is that, whether we decide to use frequency or wavelength, we do have a quantitative way to describe colour.
The point? I do believe you mean your point, Heliomance. And yeah, I GOT THAT. To which I responded with my own point: We have more than one quantitative way to describe color, and a pair of colors could be called "more similar" or "less similar" to each other than another pair of colors depending on how the difference between them is quantified! That's what I meant when I said "I'm not sure that there's an unbiased measure of 'similarity' in this context."

The two measures will not consistently produce identical results! How is that not important?


I'm allowed to suspect whatever I want to suspect. That's what a hypothesis is. It remains a hypothesis until either disproved or sufficient supporting evidence is obtained.
I'm not talking about what's allowed, I'm talking about what's rational. And there are degrees of suspicion, quantifiable as probability estimates. When you receive evidence for or against a hypothesis, you should consequently regard it as more or less probable. (Bayes' theorem (http://en.wikipedia.org/wiki/Bayes%27_theorem) is the relevant formal mathematics.) Hypotheses can't be empirically "proved" or "disproved"; it's just that the probabilities we assign to them just get driven near to 0% or 100%. But "near" is relative, not absolute.

(Assigning a theory a probability of exactly 0% or 100% means planning to never interpret further evidence as contradicting what you presently believe, no matter what you observe. At which point you've abandoned empiricism with regard to that particular issue.)


EDIT: Whoah, I looked at the stoplight photos, and they all do seem to be bluish instead of green! It could be like how embers look purple through some cameras but red to people looking at them. I'll look at the stoplights on my way to the city tomorrow.

EDIT 2: Nopers. All of the stoplights are completely green. Some of the green arrows have a hint of bluish in them, but there aren't any blue or even tealish lights. Maybe it's the cameras. Maybe other places have blue lights and there just aren't any in this city.
Looking at stoplights as I've walked around, I've found that some of them are at least close to cyan whereas others really are decidedly green. It seems that there can be considerable variation between the lights even in a relatively small area, sometimes.


"White" people are usually pink or pinky-brown.
More of a peach; that is to say, a light orangish color. Whereas "black" people are brown, i.e. ... a dark orangish color.

Human skin doesn't really vary much in hue.

[Heliomance]

How? What would it even mean to "correct for" this?
The easiest way would be to measure both frequency and wavelength, and see if it's even an issue with the colours used. It could well be that there isn't a problem with those specific colours, that wavelength and frequency agree. If not, well, I'm sure someone somewhere has done an official scale of colour similarity. Hmm, this (http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CCQQFjAA&url=http%3A%2F%2Fwww.imbs.uci.edu%2FCOLLOQUIUM%2F1 2-13%2Fkomarova-kameson.docx&ei=-xNwUI65CPTJ0AWsgIHQBw&usg=AFQjCNHd9VZuWEBRQm59ZLGsUv_uEC-Bgw) looks relevant. Bit dense for me, though.



I'm not talking about what's allowed, I'm talking about what's rational. And there are degrees of suspicion, quantifiable as probability estimates. When you receive evidence for or against a hypothesis, you should consequently regard it as more or less probable. (Bayes' theorem (http://en.wikipedia.org/wiki/Bayes%27_theorem) is the relevant formal mathematics.) Hypotheses can't be empirically "proved" or "disproved"; it's just that the probabilities we assign to them just get driven near to 0% or 100%. But "near" is relative, not absolute.

(Assigning a theory a probability of exactly 0% or 100% means planning to never interpret further evidence as contradicting what you presently believe, no matter what you observe. At which point you've abandoned empiricism with regard to that particular issue.)
It's quite easy to disprove a hypothesis, all you need is a single counterexample. Regardless, as neither of us have actually presented any new concrete evidence, I've not had anything to modify my hypothesis probabilities with. The paper I linked above might well answer the question; unffortunately I can't understand it.

[nedz]

The easiest way would be to measure both frequency and wavelength, and see if it's even an issue with the colours used. It could well be that there isn't a problem with those specific colours, that wavelength and frequency agree. ...

Erm, for any wave: v = f λ
where v is velocity, f is frequency and λ wavelength.
For light v = c, which in any given medium is a constant.

So
if you measure f you know λ, because λ = c / f
also if you measure λ then you know f, because f = c / λ

Does this help ?

[Devils_Advocate]

The easiest way would be to measure both frequency and wavelength, and see if it's even an issue with the colours used. It could well be that there isn't a problem with those specific colours, that wavelength and frequency agree.
Even so, I have little doubt that one could devise some third scale that would "disagree with" both. My point is that the scale chosen matters.

Treating similarity as something that you can measure means taking something you can measure and calling it "similarity". But this is simply playing games with language, is it not?


If not, well, I'm sure someone somewhere has done an official scale of colour similarity.
Official does not equal non-arbitrary.


Hmm, this (http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CCQQFjAA&url=http%3A%2F%2Fwww.imbs.uci.edu%2FCOLLOQUIUM%2F1 2-13%2Fkomarova-kameson.docx&ei=-xNwUI65CPTJ0AWsgIHQBw&usg=AFQjCNHd9VZuWEBRQm59ZLGsUv_uEC-Bgw) looks relevant. Bit dense for me, though.
Sounds like an attempt to explain color perception and maybe to quantify how similar colors appear to be to human observers, which is basically the opposite of what you want.


It's quite easy to disprove a hypothesis, all you need is a single counterexample.
Once you've certainly got a counterexample you've certainly disproved the hypothesis, but how can you justify certainty in the counterexample? Infinite regress, problem of induction, etc.

Furthermore, probabilistic hypotheses -- e.g. "This coin will come up tails half of the times it's flipped" -- don't really have counterexamples.


Regardless, as neither of us have actually presented any new concrete evidence, I've not had anything to modify my hypothesis probabilities with.
But evidence doesn't need to be concrete to be for or against a proposition, does it? I'll admit that I'm not really familiar with the meaning of "concrete" in this context.


Erm, for any wave: v = f λ
where v is velocity, f is frequency and λ wavelength.
For light v = c, which in any given medium is a constant.

So
if you measure f you know λ, because λ = c / f
also if you measure λ then you know f, because f = c / λ

Does this help ?
Nope!


X - Y is not directly proportional to c/X - c/Y; you cannot multiply one of those expression by a constant to get the other. As I said, you can even see this in Erloas's graph. Violet light covers a larger range of frequencies than red light but a smaller range of wavelengths.

[nedz]

Going back to the OP

The Romans and Byzantines used Red, White, Green and Blue for their chariot racing (http://en.wikipedia.org/wiki/Chariot_racing).

Maybe they didn't have Yellow paint ?

[Heliomance]

Sounds like an attempt to explain color perception and maybe to quantify how similar colors appear to be to human observers, which is basically the opposite of what you want.

If actual sound evidence can be found that contradicts my hypothesis, I will naturally abandon it - that's how science works. You have not provided any.

[Artemis97]

Just came across this (http://www.youtube.com/watch?v=mf5otGNbkuc) while watching Netflix. I thought it was appropriate to this conversation and that you folks might find it interesting. Enjoy!