As a white guy with dark hair, I'm attracted to women of all different races, skin tones, hair colors, etc. when it comes to physical attraction, my attraction always has to do with the golden ratio (look up the mathematics behind beauty), I find that the closer a womans face is the golden ratio and being perfect, the more I find her attractive, which is the same for most people, I'm big the face, race doesn't matter.
Also, on a primal level, you may find that people who LOOK opposite to you might be attractive more to you, but chances are you're one of the few of your race who is apart of a haplogroup generally associated with a certain race. For example, if I really liked black girls, chances are I'd be one of the white people who are apart of the haplogroup generally associated with people of African descent. There is actually a correlation between haplogroups and the interracial marriages that do work out and last. Haplogroups can transcend race. Though there are people who could be classified as apart of a haplogroup associated with another race, due to intermixing you don't know about.
When it comes to your subconscious, genetics/haplogroups and attraction, its generally "if you're like me, you like me", same even goes for friendships.