If you’ve seen videos of cosplay or the various ‘Cons’ the first thing you notice is that they feature all sorts of quirky, colorful (and often brilliant) costumes, which is why it’s understandable if you thought that that was what comic geek culture was all about (besides costumes and the–virtual–worship of certain movies and comic characters).
And for the most part, you’d be right, though there are instances when a comic character that began “life” as a white person, and is reinterpreted as a person of color in the movies (Oddly, when a male character was reinterpreted as female, in the case of 2004 reboot of Battlestar Galactica, when Starbuck was underwent gender reassignment, fans only offered token resistance while most were relatively sanguine about it) when you often see the ugly side of fandom.
Before I begin, you’ll noticed that I deliberately don’t use the term “race” because, besides being a misnomer, it has always bothered me because white people are genetically identical to black people, yellow people, beige people, and so on.
I bring this up because the reaction to John Boyega, dressed as a stormtrooper in the beginning of the Star Wars: The Force Awakens trailer, has been pretty distressing for some members of the fan community.
Comic book fans tend to be sticklers for detail, which to a degree I can understand. If someone has been following a character for the better part of their lives, it probably feels amazing to see the character on the big screen; till that is, they see that the character has been interpreted in a manner opposite to what they have known and anticipated.
That being said, it feels that whenever an actor of color is cast in a prominent role in a comic book movie, some in the fan community lose all sense of propriety, and logic goes out the window.