Gotart I just call myself American. :)
No, I'm not afraid of being called racist, because I'm not. But it is odd how some things just seem off limits to say...this summer there was a group of yound guys playing basketball at the park. They were all white except one, and two little girls were talking about them. One girl said "I know him, that's Robert. The one with the...um, green shorts and black shoes." She so obviously didn't want to say "Robert, the black guy," and I understand that, but at the same time if only one of the boys had been white, she would have said "Robert, the white guy.
I don't think there's anything wrong with using it as a descriptive term. The only reason it would be is if the term black, or white, or Pakistani, meant something negative in your mind, and it doesn't in mine.
Humans...what funny creatures we are, really. :)