In celebration of St. Patrick's Day I planned a rainbow sort for my class. I found the idea at this website. I drew up a simple rainbow and gathered all he tubs of toys we had and explained to the kids what we were doing. As a group we went from one color to the next having a blast finding enough toys for each color.
After the sort we decided to leave the toys that way for a while, but then the kids wanted to play with some of them so I put them all together in a tub for them to 'Play with a Rainbow'.