A spray-on ink that can infinitely change colors, designs, and patterns when blasted with different wavelengths of light. It uses a series of photochromic dyes (which work similarly to glasses that automatically darken in the presence of sunlight) that can be applied to almost any object using standard painting methods like brushes or sprays. The ink was created by mixing cyan, magenta, and yellow photochromic dyes together to create a single solution that works like paint, but one that’s invisible until exposed to a very specific light show.