When rumors first emerged that former Disney channel star Zendaya would be playing Mary Jane, a role previously played by Kirsten Dunst, in a "Spider-Man" reboot, some people on Twitter lost their minds, insisting that the character simply had to be played a redhead. 

Some pointed out that "redhead" appeared to be code for "white."

BuzzFeed editor Jarett Wieselman responded to tweets with a photo of Zendaya with dyed red hair.

James Gunn, writer and director of "Guardians of the Galaxy" and "Guardians of the Galaxy Vol. 2" tweeted a more direct sentiment.

He then expanded his thoughts in a Facebook post that has gotten 14k likes and almost 3,000 shares.

Here are some key excerpts from that post.

(Emphasis mine.)

"People get upset when something they consider intrinsic to a comic book character changes when adapted for a film. I get this."

"[...] That said, I do not believe a character is the color of his or her skin. When Michael B Jordan was cast as Johnny Storm I didn't understand the uproar. The primary characteristic of Johnny was not, to me, that he was white, or that he had blonde hair, but that he was a fiery, funny, big-mouthed braggart of a hero. I was happy that he was going to be played by one of the finest and most charming young actors out there.

"Yesterday, a rumor broke out that the character of Mary Jane was being played by a young black woman, Zendaya, and all hell broke out on the Internet (again). I tweeted that if people find themselves complaining about Mary Jane's ethnicity they have lives that are too good.

[...]

"I can't respond to the racists - I'm not ever going to change their minds. But for the thoughtful majority of you out there:

"For me, if a character's primary attribute - the thing that makes them iconic - is the color of their skin, or their hair color, frankly, that character is shallow and sucks. For me, what makes MJ MJ is her alpha female playfulness, and if the actress captures that, then she'll work. And, for the record, I think Zendaya even matches what I think of as MJ's primary physical characteristics - she's a tall, thin model - much more so than actresses have in the past.

"Whatever the case, if we're going to continue to make movies based on the almost all white heroes and supporting characters from the comics of the last century, we're going to have to get used to them being more reflective of our diverse present world. Perhaps we can be open to the idea that, although someone may not initially match how we personally conceive a character, we can be - and often are - happily surprised."

Though many people "liked" Gunn's status, a few still had bones to pick.

James Gunn/Facebook - facebook.com

And Gunn even conceded on one point about Hollywood's race problem.

James Gunn/Facebook - facebook.com

Ultimately, it's refreshing to see a Hollywood insider speak openly about race and casting in major Hollywood films.

Perhaps, to quote Gunn, they'll be "happily surprised."