Black skeletons or white skeletons?

By the way, regarding skeletons – the established lore suggests that black skeletons were the elite, while white ones were slaves to the black ones.

I'm judging based on the games I've played, for example, Diablo 2 or, as a more striking example, Spellforce.

Sorry, but black skeletons are just the invention of individual developers for the sake of supposed diversity (because I don't consider different-colored models of the same monster to be diversity, except in rare cases). In the vast majority of games, if skeletons exist, they are ordinary white ones, without any color variations. So, it doesn't really align with the established lore.