I was mistaken, hair is changing to blonde as well as gray after I make over NPCs. There seems to be no rhyme or reason to the bug, but my making over NPCs is triggering these changes, whether its aging or just changing hair shades.
It's happening with all hairstyles, men and women, and any colors I pick.
After I makeover a sim, the next time I see them they have the wrong hair color. It's hard to get a screen shot since I dont know when it's going to happen.
Making over NPCs are either triggering them to age (and that would take away all incentive to even buy makeovers) or there is a glitch changing hair colors on adult NPCs.
Here is one example of an NPC I made over the day before this photo, having hot pink hair. Next day, it's dark.
Other NPCs I have made over are blonde the next time I see them, when I have not chosen blonde.
