Chalk Paint! I've never bought it because I've heard it stains the sidewalk. So, We made our own that does NOT stain!!! WooHoo!
Mix equal amounts of cornstarch and water. In this case I used 1 cup of each.
Add a few drops of food coloring.
Stir it up.
Mix a few colors and get out some brushes.
Then, have some fun.
When you're done, spray it clean with the hose. If you live in Wisconsin, just let the rain do the work. Who needs a hose in June (stupid summer weather).