It seems like the base color is just fine but the level of sheen is very very high on black hair;

It's especially apparent on many of the female Highlander hairstyles, where it's so reflective you can get brown highlights from the Black Shroud background.

This might be a result of the Character Creator's lighting, but I don't think there's any environment where black hair should be so reflective.

I like the fidelity of the hair textures, but it'd be very nice to have black hair (and likely other dark colors) be more light absorbent.