Roleplaying thoughts

[JusticeZero]

I'd say it's not impossible (though highly unlikely) for someone trained and raised in the Sith traditions to turn to the Light Side. Thing is, they'd end up being pretty much the same as a Jedi and would reject the Sith ideals. The extreme selfishness and need to dominate that is the core of the Sith is entirely at odds with the sublimation of the self and attempt at harmony with the Universe that is the focus of the Jedi.

And see, this is how the propaganda reads. There is nothing in the core Sith beliefs that demands selfishness; it's about being passionate and trying to change things. Go look at all of the people protesting any of the several social injustices of the day; every single protester and activist there is following the Sith code. What they are doing is indeed the epitome of the Dark Side.
It's just that the Sith Code doesn't exist in a vacuum. The order itself has a lot of jerks in it right now. They have some good reasons to be angry, mind you. The Jedi, as an organization, is also pretty thoroughly evil in a lot of ways, but they're the ones that are connected to the side that gets to write the history.

Light and Dark aren't so much about good and evil, it's more balance and imbalance, attuning yourself to the flow of the universe or trying to force it (ha) to do what you want, about accepting and adapting or trying to dominate it.... a believer in the Sith code could conceivably come to the heretical conclusion that the truest strength is surrender and acceptance rather than conflict and dominance but you'd have to do some really twisty thinking to believe that the Sith code can be interpreted this way.

We're in agreement on that point at least, which is why I find "Light Side Sith" and "Grey jedi" to both be a mess. The former is a severe mess of dysfunctional theology, and the latter is just someone who agrees that the Jedi Code requires certain things, which they just don't want to do.

Also, there is nothing unreasonable about even a blackhearted Sith adopting the Light Side - the Dark Side is said to be the fast and easy way - but the flip side of that is that the Light Side can be seen as a sort of Magicarp Power, which a long-planning Sith might find appealing.