Have you seen this super fun video from Sesame Street? The students (and I) loved it! After we watched it through once, they wanted to hear it again so we just replayed over and over while they worked and sang along!
What were they working on? In the first class, painting whatever they wanted as long as they were mixing primary colors to create secondary colors. We took a little break to work on clay projects then came back to these at the end of the school year. In the second class period, I gave one class paper mosaic tiles to add designs on top of their paintings, and the other black tempera paint to add their designs. Easy peasy.