Is it racist to say that I wouldn’t generally go for a black or white person?

One of the British Big Brother contestant on this year’s season stated she would go for dark skin but not black. She further stated that she wouldn’t generally go for black guys. When approach by a fellow contestant about her statement, who happens to be a black woman, she said "that’s my preference, you probably wouldn’t go for a white guy". When I heard this two things popped up in my head. One being, was what she said just a matter of preference or actually racist? Secondly, why did she assume that her black housemate wouldn't go out with a white guy? 

With the first question I think it is important to know that people do have preferences. To me race is not a qualification to how attractive someone is to me. If you are hot you are hot. But that said, I know people who prefer a particular race. I do not think there is anything wrong with preference; the issue only comes when we determine our preference based on the media’s portrayal of certain races. If the big brother contestant genuinely does not find black men attractive without any particular negative feelings towards black men as a whole then fair enough. Preference is fine as long as there are no negative racial attitudes towards that particular group.    

With the second element I am particularly interested in 'why' she said the other housemate, the black woman, would not go out with a white man. Do people generally assume that you would not go out with a particular race because you belong to a different race? This makes me wonder do people generally think I could not go out with a white man because I am black. Can this explain why white men do not approach me? Yesterday I was in a shop and noticed that a man was looking at me, but didn't say anything. This is generally the experience I have had with white men.