Why are there few black people in anime?

[following Jesus word]

I'm not saying this to say that the Japanese are racist at all, but just wondering. They certainly have a lot of white people with blonde and brown and red hair and pale skin, but few black characters. They like portraying Americans a lot and incorporate a lot of English (or English) in anime, but why not black people? African Americans are certainly a big part of America.
Or does Japan prohibit drawing black people by law?
I should have said "(or Engrish)".