Remember those shirts that changed color when warm hands were pressed against them? Well these Moving Color glass tiles take me back. At room temperature, the tiles appear black (or whatever base color you choose—there’s over ten to select from). But as heat is applied to the surface the tiles start to change color and run the spectrum of the color wheel. Once they cool, the tiles revert back to their base color. Moving Color tiles are waterproof and recommended for indoor applications only. The company claims they will live more than seven years, and backs the tiles with a one-year warranty. One square foot of 4 x 4 glass tile runs about $180. More expensive than those T-shirts, sure, but a little more modern. All you need now is a bathroom sound system that plays Pink Floyd on a loop, and you'll have your own psychedelic shower experience.