The best example of it was when I posted
>>1372611. The contrast was perfect between Saber's skin tone and hair. The image here is also a good example, I think.
Blonde hair does tend to work well with dark skin, as does white hair. I think it has something to do with the saturation of the color, and that it isn't a golden yellow. Paler hair doesn't seem to conflict with dark skin as much as a primary red or blue does, if at all. And hey, we all look at women with wild colored hair here. Why the hell should we stop that trend? Why should we change that much? It seems... rather conservative when it's an open potential to put to use.