I've been thinking about this lately - not really because I'm currently writing about it, but because I was reading someone ranting about most fantasies having all-white casts, and because I've occasionally written about non-white characters and wasn't sure what to do.
This is probably most prominent in medieval fantasy, since most of those are based on Western Europe from the Middle Ages, which was mostly populated by whites. But fantasy doesn't have to adhere to that, obviously; these are made-up worlds. And even in non-fantasy writing, there will probably come a time when you write about non-white characters.
See, the problem I often have is that I want to write a non-white character - not to be politically correct, but because it fits the character - but I don't want to say something like "he was black" or something as if to parade the fact that I'm using a diverse range of races in my writing. In the end, when I wrote a story about a black family with a first-person narrator who wouldn't see any reason to say, "We were black, y'know," I just didn't mention it at all and then became frustrated because no one would know that I was intending them to be black, not white as the default tends to be.
In reading Fallen Angels by Walter Dean Myers, which is about a black soldier in Vietnam, I noticed that he didn't often directly mention whether a character was black or not, but it became obvious from the way they talked with each other. The narrator would call his fellow black soldiers "brothers," and some of them would just talk differently than the white soldiers. He also used some racial tension to indicate who was which.
I can see how that would work in the real world, because you can use colloquialisms or accents or even names to indicate they're not just white, and can tap into other things like that, and the readers would be able to pick up on it. But what if you're writing in a world other than our own? What if you've got a land where everyone has tan skin and narrow Asian eyes, and to them it's normal and not worth mentioning? I mean, when they saw another person, they wouldn't describe him as, "a tan-skinned man with narrow, slanting eyes" or something, because everyone's like that. If a foreigner came along, they might describe him as "a pale-skinned man with wide, round eyes," but then wouldn't the reader just picture a bug-eyed albino or something?
Ideas, anyone? How do you deal with other races in your writing? Do you?