Silverbrow Human

[ONI]

They gets Dragonblood subtype, does that means they get the darkvision/immune sleep and paralysis?

[PoeticallyPsyco]

No, that would be the Dragon type.

Dragonblood is a subtype, like (human) or (elf) or (Evil); a Silverbrow Human is a "Humanoid (dragonblood, human)". It doesn't do anything on its own, IIRC, but it does qualify you for some truly fantastic character options, like the Draconic Aura or Dragonfire Inspiration feats from the same book, or the [Dragon] soulmelds in Magic of Incarnum.

If you want to add immunity to sleep and paralysis (and a few other perks) to a character, check out Dragonborn of Bahamut (aspect of the mind), which does give you those dragon traits as you gain levels, at the cost of most of your original racial features. (Incidentally, the template also gives you the (dragonblood) subtype).