Probably also has something to do with common features that members of the race share

I know people use that argument a lot, but even if there are features that are more common to certain races, not everyone who belongs to a given race shares the same features. Like, does Lupita Nyong'o have the same features as Stacey Dash and do they both have the same features Rihanna has? What features do they really have in common that other races might not also have?

I'm familiar with the example you use from India. My ex-boyfriend was Indian. He was mid-tone as far as skin and from Gujarat, and he would tell me how his extended family looked down on darker skinned Indians.

And then there's my Korean friend who won't go to the beach without two towels--one to lie down on and one to put over her so she won't get tan.

There's definitely a lot of complicated sociological shit going on there, but I'll still stick by my opinion that it's racist to say you find black women unattractive--black women have a huge range of skin tones, facial features and body types.

It's another issue whether one might just "not find darker skin tones attractive" or whether that person is conditioned to not like darker skin tones because of societal/cultural factors.