Dunno. I remember my little sisters getting giant makeup boxes from the toy store full of really cheap tiny makeups in hundreds of colors. I think they were like 7, 8, and 9 when that started. They weren't allowed to wear it to school, but to the mall on weekends was ok.
I don't remember anything bad happening from it, except I was the only boy at school who knew how to paint nails and braid hair. My sisters often asked me for help.