The problem with movies is that when they add a coloured person in most cases it feels out of place because they try to change something that was already written (for example in a comic book).
Just be original put coloured people in as normal characters and not bluntly obvious tokens.
There is plenty of movies out there that do this well even going back to the 70s-80s. Watching some of those i didn't FEEL like FMD a token coloured person was thrown in. They had a role that fit.
Same goes i reverse. If the movie's main objective is to focus on a certain race or whatever as part of the story. i honestly couldn't care less if there was 0 white people in them. Just give us a good movie lol.
I see the bolded stated a lot, specifically with comic book movies, and it always bugs the hell out of me. Most all of the famous comic book characters were created prior to 1968, when diversity actually was a huge issue. You take those same character concepts today and create them and you are going to have a more diverse group simply based on how the world is now.
As far as the topic question goes: I feel as though diversity in a story, regardless of what medium it is told in, is up to the creator. If they want it filled with half black half hispanic transgender gay people because it fits their vision, great. If they want it filled with white supremacists or black panther party members because thats what the narrative and tone calls for, go for it. The idea that people consuming art and entertainment feel entitled to tell people how it should be created is quite pathetic and goes against the very idea of art in my opinion.