It would be less insulting if white writers, academics, and producers would just say, Its beyond the realm of my capabilities and experience to portray 3-dimensional characters of color who aren’t foils, gags, typecasted to the maximum, or supporting characters. It would much less insulting to just admit this rather than:
1. pretending that they can and failing,
2. supposing that they can and not trying,
3. and/or appropriating aspects of other cultures and misrepresenting them to entertain largely white audiences.
Just say you can’t do it. Put us all out of our misery. I’m not saying they all suck at this…just that most of them probably do.
Ever more real,
Ms. Queenly
Elia's Diamonds 
The thing I often wonder is this: Why they can’t just write a carachter into the movies and/or books without making a deliberate desicion? Just write a person in to the story and let him/her be, and perhaps mention somewhere that this person is black. Or do not. Just let it be. Now, it seems, they really make an effort to have a BLACK carachter in the story and that of course calls for stereotypes and clishes and so on.
I have seen some brittish tv shows where they have black people but the subject of race does not even come up. They are who they are but they don’t act funny, speak “black”, act “black”, and very often are depicted in the same professions as the whites. In many cases they are politicians, police chiefs, in one series it was a black female primeminister etc.
But in american ones, some how they have to be portrayed so that they are The Other.