Toddler Art Time: Painting Rainbows with Tissue Paper Rolls

I have collected many, MANY tissue paper rolls hoping they would be of some use someday. So after I once saw how he quickly painted a few building blocks, I cut some arches out of these rolls to paint. He called them rainbows and happily painted them in different colors, even grey. With this idea, every time he says "More!" I am more than willing to cut more rolls!