We have just started our journey into the many ways we can play with the light table. Our most recent trial was playing on the light table with bags of paint. I let Logan select the colors. For the first one he only wanted red with glitter in it.
The second one I suggested we use two colors and he picked blue and yellow. Which was perfect since when he mixed them together they created green. We used some left over Crayola finger paint for this activity. Since it is less thick than other paint, the light easily shone through.
Don't have a light box? You can yield the same results by taping a Ziploc bag to a window. This is a quick, essentially free (if you have items on hand) way to learn about colors!