Changing the racial identity of characters has become a contentious issue amongst fans of superhero comics and their adaptations in other media. The awful practices of casting white actors to play people of color, or of turning previously non-white characters into white characters, is all too common in movie adaptations of books, cartoons, TV shows, or even real life stories -- but rather surprisingly, superhero comics and their adaptations have mostly avoided this problem.
In comics, the controversy takes a different direction. Several white characters have become non-white, mostly in movies, and sometimes in reboots. Michael B. Jordan as Johnny Storm in the new Fantastic Four; Helena Bertinelli aka the Huntress in the New 52; Nick Fury in the Ultimate Comics line and on screen. These are changes that agitate some readers -- but realistically, the changes don't go far enough. Superhero comics have a cultural bias towards white characters that has everything to do with their institutional history and nothing to do with what makes sense to the stories.