I, personally, am trying to line up my three tribes by hair color - the black-haired Dru'gotti, the red-haired Kiegan, and the blond Leland tribe. It's just another challenge that I'm trying to accomplish.
Just beware that sometimes random hair color emerges. It is built in to the game. For example: I mated two blonde villagers and ended up with a black-haired baby.