You may think you've seen these before, but you haven't. Although traditional clear soap bubbles give you a rainbow effect in the right light, Zubbles are the first truly colored bubbles-nearly opaque, with a single vibrant hue. The problem, which took Minnesota toy inventor Tim Kehoe more than 10 years to solve, was to create a dye that could not only tint the thin wall of a soap bubble but that wouldn't leave a stain when the bubble broke. His solution: invent an entirely new dye that simply disappears. Agitation (rubbing your hands together) or exposure to the air transforms the dye's molecular structure from brightly colored to colorless in minutes or hours, depending on the surface the bubbles break on.