I got this fun activity from The Toddler’s Busy Book by Trish Kuffner. All you need is an ice cube tray, water, red, yellow and blue food coloring and 3 ziploc bags.
Before we went outside to play I mixed water and food coloring (enough for 2 ice cubes of each color) and poured it into an icecube tray. After lunch I took the frozen colored ice cubes and places them in ziploc bags. Place a red and a yellow together, a red and a blue cube into the second and a yellow and blue into the third baggie. Owen had fun moving the ice cubes around in the bag and watching what happened as the two colors melted together. “It’s geeeem!” (green).