I searched the forum but didn't find anything regarding this. Unless I failed at searching, which is entirely possible. But I've wondered for a while... why exactly do most of the One Sith tattoo themselves and color their skin red? Considering the various races that make up the One Sith, I never took it as a natural genetic modification they made to color their skin red, but rather something they did as a rite. Maladi was not born a Sith (IIRC her origin correctly), yet she subsequently wound up with this ritualistic look of the One Sith. But if it's ritualistic, why then did Krayt A) never do it himself, while simultaneously B) finding a need for this to become a staple of One Sith society? I know there were others who did not (Darh Nihl immediately coming to mind) but the vast majority appeared to be of the crimson variety. So... was this ever explained? More of a curiosity. It obviously doesn't break my enjoyment of the fiction, but hey, I have these geeky questions from time to time.
Color coordination for Jan's pretty pictures! No, seriously, it was probably a unity thing. Just as soldiers wear similar uniforms, the One Sith may have wanted to have this matching look, especially considering how big they are on being OMG WE ARE ONE!! Also I read somewhere that the tattoos were apparently an intimidation thing, or whatever. I think it works. The red color also may have been a throwback to the original Sith species. I always took the non-redness of Krayt and Nihl as because they are different. Krayt is DA BOSS, and does not have to follow rules, can do what he wants, whatever. Nihl joined the Sith after he had already had a life, and after he joined, was always apart. The skin is another aspect of that differentness.
In addition to that... -Tusken culture apparently liked tattoos -tattoos are painful, Krayt was big on embracing pain after encountering the Vong -maybe he encountered Darth Maul, or another Nightbrother, sometime during the Clone Wars and he liked the intimidation of it
Yeah, may have been a test through pain thing. You don't have to like it, but you do it because Krayt told you to.
The specific Nihl thing, you may be interested in this: http://boards.theforce.net/threads/darth-nihl-why-the-different-look.25007237/
More tattoo stuff: http://boards.theforce.net/threads/why-do-sith-lords-like-to-have-tattoos.27877910/#post-27880395
