Disguise Stix from eBay. I like the popsicle format because you don't get hands dirty to apply it;you just hold it under running warm water and apply. You put it in ziplock and take with you to show and offer to paint everyone else in the audience
It washes off with soap, lots of soap. The paint itself is actually soap based. Makeup removal napkins help a lot. I have Royal Red and Midnight Black for Turisas purposes.
See avatar to get an idea of what colours actually look like.