Lost Queen : Sort of, at least in a way. There’s a spell we use that causes vitiligo to bleed secondary colors from Kuros who are going into priest/priestesshood. It is permanent, but instead of making the secondary plates lighter, it drains the color. Often leaving them grey, or black depending on the original color’s lightness.
Vitiligo didn’t naturally happen in our species, however. At least not that I’ve heard.
Weirdlanders 