Not just any old chalk though- homemade chalk in whatever colors you want, however bright you want, and you paint it instead of draw with it. Chalk paint, its a good thing (channeling Martha).
It dries looking just like regular old chalk, just brighter.
Here's how you do it:
Step 1: Mix equal parts water and corn starch.
Step 2: Add food coloring to desired color.
Step 3: Go outside and paint :)