Yeah, except the answer touches another topic.
"Look, Serge's hair is blue!"
"So what, it's because the artists drew him this way."
"And...? I was asking for an answer in the plot."
"So? Screw you, we're looking for the SIMPLE answer, not the one that actually has to do with the PLOT of an RPG..."

You're not the idiot i'm talking about, it was this other guy >.>
Now.
1) You just insulted Magus. What, is he a preppy, drag queen now? Get real. Come on, he also has red eyes and pointy ears, and is pale..
2) Umm, The people of Ioka had blue and pink hair... And that's genes... even Serge and Riddle, and Karsh has purple..
3) Do you seriously believe Zeal would do stuff like that when her only goal is to become immortal and all powerful?
4) Schala is super human. The thing that kept her from doing stuff like rebelling was her ethics towards her mother, elders and people. Her sustaining the TD is enough to show that.
Don't make this seem light hearted. I love Schala, and she's my favourite NPC of all time....

1) Old habits die hard... Yes I do believe many people would do things like that if they were able (if it were in thier upbringing).
2)How do YOU know it was genes? Maybe they had blonde hair like ayla or kino, but stained it with ochres from various rocks.
3)Hey, Hitler kept is moustache trimmed and well tended, even after he had abandoned alot of social affairs; leaders have to keep face for the plebeians.
4)Because of those ethics, she would keep her blue hair, so as not to ashame the rest of her family. Schala may be superuhman in a one in a billion way, and may be your favourite NPC (and one of mine) but we must remain objective

. Just because she is these things, doesnt mean she is not under the sway of human influence or emotion.
In the end, schala is only human, whatever powers she may or may not have.