Make colored sand art by stirring a chalk stick in a bowl of salt. it changes the color. Stir less for light color and more for dark richer color. (I used to do this with salt and food coloring. but the chalk stick idea is brilliant!
Bowls made of confetti! Great recycling art project--save all those leftover paper scraps (put in small bowls at each table). Collect a bunch and have the kids cut them up; Then make bowls made from confetti.