BLACK! Nooo, how could they do this to a minor character who never gets any real lines anyway???

Isn't it sad when Rowling has to point out a character is black or asian, because we'll just always assume that if race isn't mentioned, they're austomatically white? I remember her describing Angelina Johnson in the last book as 'a tall black girl' which struck me as odd, because no one is ever 'a short, fat white kid'.