After she was finished mixing the colors, we put the ice cube tray into the freezer.
Later that day, we took it out and I let T begin to paint with the colors she made.
I let her use both regular and watercolor paper. They both worked equally well.
We used food coloring for this activity but liquid watercolors would also work.
This was another fabulous art idea found in First Art Experiences for Toddlers and Twos by MaryAnn F. Kohl.