Stampin' UP! offers some really cool watercolor crayons. You can color with them right on the rubber or you can color on paper and use an aqua painter or a blender pen... results are way cool for all three. You can see how to color right on the rubber from the pics I have posted below from yesterdays Funstamper's Meeting up in Hesperia! The results are stunning! If you are worried about never having access to certain colors again ... the watercolor crayons are a great way to hold on to the retiring colors!