Guinea Pig finger painting?

So I want to have a painting of my piggies feet, and write they're names on there and hang it up on my wall where they're cages are. But I'm not sure that I can because I know that some paints have bad chemicals, I've seen people have they're dogs finger paint with Child Safe paint. or I could make home made paint (My mom use to do it all the time when I was younger) as far as I know there isn't any harmful chemicals in home made paint. But I think it'll be something nice to do, having something of my 4 lovely piggies C: What do you guys think? and I will wash them immediately after painting!