I colored 50 cans worth of foam once and it was pretty easy. The trick is to have it all contained (in a bucket, tub, whatever) and to stir like crazy. It doesn't take much to add a little color (I use those food coloring bottles from the grocery store). Stirring with your hand and arm to get it all mixed in works really well. And to go beyond the primary colors simply mix it up with others. Hope that helps and have fun!
I find food colouring works well. I've tried using bottles of ready-mixed poster paint and its hit and miss. Some foams (usually the more expensive brands) will mix very well. Cheaper brands will just dissolve into nothing when paint is mixed in, so you have to experiment.
She did tell me she used a lot and after she wiped off the shaving cream her face was still blue. A few scrubs with Joy soap and she said it was back to normal.
A few more pics and this was such a dynamite color it looks really good on film.
If you use food colouring (like I did in this picture) I use about a bottle for a large can (400ml) of shaving foam. It may stain clothing, but at this concentration I've not experienced it staining skin as the colour is suspended in the foam.
We've mixed a small amount of gunge into the foam for making pies before, that seemed to work quite well. Other than that food colouring or kids paint. The food colouring can stain, thats the only thing.
I use food coloring to color my pies. I also add a little water, to make it more creamy. When I say little, I'm talking about a 1:10 ratio, based on weight. I also dillute my food coloring to about a 1:1 ratio. This limits skin staining if you get it on your skin.
Mix well, I usually fold, to bring up the water and coloring and make the coloring mostly even.
Love you, too
