Don't see why people in the comment section are making such a big fucking deal about what color Miku is. It's fan art. The shit exists for literally everything. I could make the argument of 'why change the original color of something/someone that someone else made instead of making your own original character. Don't whine for someone to make more representation; do it yourself so you won't be disappointed,' but honestly, I don't care. In the end, it's not why I fav art pieces. If I think it looks neat or is something eye catching, I'll add it to my favs.
I favorite this not because of 'why' you made her black, but because I think it looks neat. Carbon Miku happens to be my favorite model of her so I'm not against a darker Miku.