A fun M week activity was mixing colors. In one bag, I put shaving cream and food coloring. First I added some yellow dye, then the shaving cream, and then some blue dye. I sealed the bag and taped it shut to avoid any tragic messes.
Trip was somewhat interested in it, so he played with it a little and the colors started to mix.
Another, probably better way to do this activity is to mix shaving cream and paint.
The other way we mixed colors was something I saw on the Family Fun website. I cooked up 1/2 cup cornstarch, 1/4 cup sugar, and 2 cups water. This forms a thick goop that can then be dyed with food coloring. Again, I put the colors in zip-top bags and taped them closed.
Trip has been squishing them little by little, so we are still watching the colors mix a week later.