Color Mixing: Rainbow Goo

Here is a fun color-mixing science activity!
You will need:

Ingredients
1/3 cup sugar
1 cup cornstarch
4 cups cold water
red/blue/yellow food coloring

Other Materials
3 bowls
spoons
whisk
pot and stove
zipper bags

Instructions:
1) Combine sugar, cornstarch and water in a pot. Heat until the mixture begins to thicken (about when it starts to boil), stirring constantly. Cool.
2) Divide the mixture into the three bowls. Add food coloring to mixture so you have one red, one blue and one yellow.
3) Put several tablespoons full of each color into a zipper bag so you have the following combinations: red/yellow, yellow/blue, red/blue, and red/blue yellow. Tape the bag closed.
4) Knead and mix the colors.5) Talk about the new colors you made.When you are finished mixing the colors, use your goo filled bag as a writing tablet for practicing those letters or just for scribbling!