@min: By definition, you don’t realize it. It is “unconscious”. You may think you aren’t a racist, but thinking involves the conscious mind. You are not a conscious racist, you are an unconscious racist.
For example, you probably passed by a syrup bottle in the shape of a black woman at some point in the last year. When you passed by, you didn’t consciously think that the only right thing to do is burn down the neighborhood and riot on behalf of a communist style redistribution plan. This was, of course, racist on your account. And we trust that would be your natural conscious course of action (any reasonable human would riot). Therefore, your racist action (which was the inaction of not lighting the grocery store on fire) was unconscious.