This sensory activity is perfect for hot summer days! With a few simple ingredients, you can create rainbow-colored foamy fun that’s perfect for water tables or kiddie pools.
In a bowl, combine 2 tbsp of dish soap*, 1/4 cup of water, and several drops of food coloring or liquid water colors. Using an electric mixer, mix on the highest possible setting for 1-2 minutes until stiff peaks begin to form. Transfer foam to a large bin or water table. Repeat with several different colors to create the rainbow effect.
*for smaller children or sensitive skin, bubble bath can be substituted for dish soap
Source: http://www.funathomewithkids.com/2013/08/rainbow-soap-foam-bubbles-sensory-play.html