I don't see what difference that makes. Doesn't even have to be African or black, anyone with dark skin has pale hands. Even a tanned European.

There is a wide variation in skin tone, even in Africa. Everything from cafe au lait to blue-black. And no, it's not a matter of interbreeding with whites or living in sunnier climates. Often, you'll find tribes living in the same region, with very different skin tones. Anthropologists believe it's a result of sexual selection. Basically, aesthetics. Different tribes have different ideals of beauty, and it's ended up encoded in their genes.

It would be cool to have some very dark, blue-black textures.