Some years ago, before the new batch of Star Wars movies, I proactively went through my draft and made more characters female just because it seemed like the right thing to do. My two protagonists were already female (hence the working title that will definitely be replaced with something better someday, "Space Girls"). I had no agenda in mind when I made that decision at the beginning. It was just something I tried out and for whatever reason it made them more real to me and more interesting to write than my previous male protagonists who were flat and hollow and stupid, and I did this before Rey was ever a thing, before Disney even bought Lucasfilm, but now they'll make their official debut long after that fact and I suppose it will look like I'm just jumping on the bandwagon. It never occurred to me, though, to make them anything other than white. Crossing the gender barrier was somehow more intuitive than crossing the skin color barrier.
Of course, skin color is handled differently in the non-visual medium of writing, and often glossed over altogether. Most works of fiction in the U.S. have historically been written by white people to an audience of predominantly white people who will assume that all the characters are white unless otherwise implied or specified. So in the original 1980 novelization of "The Empire Strikes Back", Donald F. Glut makes no mention of Luke's or Leia's or Han's skin color, but introduces Lando as "a handsome black man". I presume Mr. Glut didn't and doesn't have a racist bone in his body. But this kind of unconscious bias is something we take notice of and try to rectify nowadays. Contrast it with Alexander Freed's 2016 novelization of "Rogue One", the most diverse Star Wars film up to that point. Every main character is given a detailed description of his or her appearance, but with no mention of skin color whatsoever.
Just a few months ago I tried to diversify my novel in like manner. Of course, most characters are never given a level of description sufficient to justify mentioning skin color or national origin, but most of them had boring "white" names and were white in my mind. My unconscious bias was at work because I'm white and I grew up surrounded by white people - my middle and high school combined literally had like five black kids - so of course that was how I would visualize the world unless prompted otherwise. I replaced a majority of these "white" names with various Hispanic, African and Asian names. All but one of the more prominent characters were also white (or half-white, in the case of one human/alien hybrid) so I changed some of their descriptions and tweaked a few of their names to rectify that. However, I didn't feel at liberty to make such adjustments to the two protagonists. They're at the center of the story I began nearly a decade ago, and to me they were like real living breathing people that I couldn't just alter as it suited me. The most I could do was decide that one of them is half Northern Paiute.
I did not use any labels like "white", "black", "Latino" or so forth, as they seem a bit heavy-handed for my purposes. Within the world of the story, national and ethnic boundaries are all but nonexistent. People of Earth live under one overarching government and collectively regard themselves as "Earthlings". Current categories of race within the Earthling species have been supplanted by the differentiations between Earthlings and other sapient beings from other worlds altogether. "Racism" is no longer about skin color so much as the number of eyes or tentacles someone has. So I just describe Earthling skin color as "pale", "tan", "dark" or what have you, and let other contextual clues like the names or accents fill in the rest. To me this makes sense and is an ideal which we should be striving for in the real world (even though our chance of meeting other sapient beings anytime soon isn't great). "Race" is a social construct that misleads people to believe in divisions within humanity that don't actually exist. Discarding it with all its associated terminology and baggage is, of course, quite impossible at this time. But I think we should be striving toward that end.
Now if anyone has actually read this far, I can imagine some of them asking, "Who the ---- cares? Why does it matter? Why are you SJWs so obsessed with this identity politics crap?" There are at least three reasons for me to have this diversity agenda.
1. The most obvious - inclusivity. If you haven't had the experience of growing up and seeing nobody of importance in the movies or on TV or in novels who looks like you, then you can be forgiven for not grasping why it affects people so much and why they're so happy for the situation to change. Even if you refuse to try to understand, it should be a neutral thing. You shouldn't feel personally attacked by people who look different getting more chances in the spotlight.
2. A related but more selfish reason - because I find it more interesting. I never gave a second thought to growing up surrounded by white people, but now it feels like a breath of fresh air whenever I have the opportunity to be around a substantial number of people who look different than me. Diversity for its own sake is just beautiful, okay? I don't know how else to explain it. And most of the name replacements I made in my novel are objectively superior to the originals anyway. Joaquin Tolentino is a much cooler name than Jacob Collins. Sorry.
3. Because, get this, it's actually necessary if I want to be realistic (which I do). This reason doesn't really apply to Star Wars because it's a fictional galaxy altogether, but my novel is set in this one, just in the future. And in the year 2153, the United States and Europe and probably all of Earth are going to be way more diverse than they are now. From what I can gather, in fact, white people are pretty much the slowest-reproducing demographic on the planet. In just a few decades they'll probably be the smallest minority of all (and since I'm not a Nazi, I have no problem with that and I'm not complaining in the slightest, just stating a fact). So visualizing a future world that's as dominated by white people as most current American movies, TV shows and novels would actually be absurd. So this means my white and now half-white protagonists are actually minorities after all!
I would agree, however, that this shouldn't matter. No such agenda as this should be necessary. In an ideal world, movies and TV shows and novels would automatically reflect the diversity that exists in real life without requiring conscious and deliberate efforts to make them so. But we, at least in the United States, aren't at that point yet.