Buy tootsie roll suckers and change the wrappers on all off them and let people choose their sucker. The lesson is you never really know what's on the inside if you make decisions only based on the outside. You can also break some of the sucker sticks and probably they won't get picked because they are not perfect...but they may be the color most ppl want on the inside.
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Thanks Davita Solter and Susan Schmit for this idea!