To avoid allergic reactions or other complications, only makeup palettes and paint that is specifically labeled as face or skin paint can be used for face painting. Acrylic and watercolor paints, even ones that are labeled "non-toxic," should not be used for face painting.
"Non-toxic" means the paint is not harmful if ingested. It can still be harmful, however, to the skin. Acceptable face paint and makeup palettes are free from ingredients that trigger allergies and other skin problems, and they wash off easily. "Washable" paints come off of clothing fine, but they are still difficult to remove from someone's skin.