gui00878 / Getty Images. A rainbow forms when each tiny droplet of water disperses sunlight. The pattern of light is always the same in a primary rainbow because each color is reflected at its own ...

These fascinating images show how color is in the eye of the beholder. ... How a dog sees a rainbow, and 12 other images that explain how we see color. March 9, 2015. Randall Munroe, Xkcd.com .