Pixar! Where are your black characters or actors?

Why were there no Black actors or characters in Toy Story 3, or Horton Hears a Who?, or in fact any Pixar movie to date. Maybe I am missing some... research time!


So I looked at Disney and Pixar. I found that the purple octopus, Stretch, was voiced by Whoopi Goldberg in TS3, but what about actual humans represented as Black? There was Joshua Sweet in Atlantis, Cobra Bubbles from Lilo and Stitch, and Frozone was in The Incredibles, but I cannot find any others - why is that?


Is there some difficulty in accurately portraying black skin in animated movies? (See Making'white'people white by Richard Dyer, The Social Shaping of Technology, 1999 - where he notes that black skin was difficult to photograph and thusly moulded cultural relations between communities.)


Even the black sounding (can I say that?) character with darker skin than the other Whos, Mrs Quilligan,  was voiced by Jaime Pressly a white actress. What is going on?