Maybe it does in your specific case, James. If so, then I can't really say whether you're racist or not.
Maybe you don't want to date outside of your race because you don't want to put up with the societal pressure. Maybe you don't want to date outside your race because of the "unknown" factor. Are those racist reasons? I really don't think so.
However, if the only thing you can come up with is "I don't want do date this person because she's non-white", then you have to ask yourself what that means to you, and what pre-conceived notions you're bringing to the table of what that non-whiteness means. If non-white = inferior, then yes, it's racism.
But as they say in the musical Avenue Q, "Everyone's a little bit racist sometimes/doesn't mean we go around commiting hate crimes..."