Oh man, I think I may be racist
Oh that's no good! What makes you think that about yourself?
There were a couple of times when I found myself judging other societies by the way they looked.
It's wrong to be racist, even if only for a minute, but most of us can't control those snap judgments that we make without thinking.  As long as you remember that all people are unique individuals, and that someone's race does not determine their value, then you are not actually being racist.
I'm really trying not to have racist thoughts.
That's reassuring to hear. Keep educating yourself about other races and you'll see there isn't really much difference between you and them.