Heh! Black is supposed to give it a bit evil type look...Allow me to explain:
The character in the picture actually has type of twin personality, Nyu is the innocent side and Lucy is the evil mass murder mutant.
Nyu is actually innocent as people can be, she could be compared to just born baby, As she lacks ability to speak or even understand speaking. Oly thing she can say is Nyu.
Lucy on the other hand is Person who could care less about living beings and kills about everyone who gets in her way. How, you ask? Well she contains several invisible extra "arms", which can block bullets, throw stuff, cut stuff and basically can rip a people in shreds. They can extent to only 2 metres though. So thats about as evil as you can get.