I don't think it's any different than saying you don't find blondes, bald people, flat noses, pointy noses or whatever else attractive. I guess it's fair to adjust my statement to say it's about physical features. If you don't find a feature - and I include skin colour in this - attractive then you don't control that, it's simply what you find sexually attractive. Everyone in the world knows that these exist. Some like long legs. Some like big butts. Every physical feature is something you may or may not like. Now, if I were to say that I think someone of a race were unattractive despite having all the physical appearance of someone that I do find attractive, that would be racist. But we're talking physical appearance. I can see the appeal of people of all races just like I can see the appeal of a dude. But I don't swing that way for dudes and there are girls I've looked at and thought they were very good looking but just don't do it for me because of various factors.
Sexual attraction is not something that can be forced. You either do or you don't. I've dated people of various races, German, Arab, Maori, Japanese... But there are some races that I've never been sexually attracted to.
One of them is ratpeople. xD