No, it's not racist, just a preference. I am very into black girls though, love the smoothness of their skin, their thicker lips when they give head and their incredible arses. A few months ago I've slept with a middle class half black civvie while abroad in America once, but generally I don't interact with black girls very much in my daily life, they're just not that common in my social circles or work environment, nor do I think I would have the level of cultural understanding to have a relationship with most of them, so black WGs are always a nice experience to have.