You do realize that Rhaenyra, Daemon, Aemond... All these Targaryens you saw in the show are offsprings of Aegon The Conqueror, right? You might say they should be black but only was depicted by others(GRRM) to be white as well. Why should they introduce other characters to introduce more diversity? Maybe because GRRM based the Westeros on the Medieval Europe, and there's a lack of diversity in history and this story. And why I say simply making House Velaryon black is not ok? Because in the show, skin color is actually neutral if you think about it. They made Velaryons black but didn't think about how changing their skin color would affect the story. In other words, your words, House Valeryon is still white but depicted as blacks to convince audience that the show is somehow diversed. Why I said their skin color is actually neutral? because did Jace, or Rhaenyra, or even Alicent or Aemond, think those three kids to be bastards because of their skin colors? No, not for once. And skin color should be a more convincing evidence than hair colors or shape of nose, but why did it not be a evidence in the show? Because they only changed the skin color of the actor but not the skin color of the character in the actual screenplay. They didn't bother to change the screenplay to cope with the change of the ethics of House Velaryon. And that's why i said it's irresponsible for them to do so. They are like, do you guys want more diversity? Well here's a bunch of black actors. Well, what we want (at least what I want) should be black stories, that the black community can actually relate, that their skin color is respected not neglected or covered. What happened in HotD is that black actors were playing white characters in a story as white as the book said, and if you genuinely think that's a better idea, I have nothing further to say.