I love giving students as many color choices as possible to paint with, but there are also times when I only want them to paint with certain colors. I finally came up with this very simple way of organizing my painting palettes, which I can't believe I didn't think of sooner. With this system, I can keep better track of which table is getting what for supplies. As an extra bonus, this system makes it easy for students to help with distribution of set up and clean up of the materials.
This system is working quite well for me. Who knows, maybe it will work for you, too?