Watercolor paints
Give your child measuring cups or small bowls, water, and some food coloring. After pouring different amounts of water into the vessels, you need to dissolve a few drops of paint in it. Tell your child, if he doesn’t know it himself, that by mixing red paint with yellow you can get orange, blue with yellow - green, and red and blue together will give purple.
If you have old sheets or white shirts, cut them into squares and roll them up with rubber bands to soak the pieces in the dye. Remove excess liquid by wrapping the cloth in a napkin or paper towel.
Helpful advice: In order not to stain the furniture, cover it with newspaper or plastic wrap, and at the same time the floor next to it.