We had a giant concrete canvas and kids itching to make a mess. We had sunshine (finally!) and a hose for washing up the mess (and cooling off.) We had the internet for ideas and a three-day weekend to fill.
What more can you ask for?
It didn't take long before paint was being applied to body parts. I'm here to tell you that food coloring does not wash off skin as easily as you might think.
Sidewalk paint recipe here. Cornstarch, water and food coloring are all you need.