In a recent episode of Veritasium, host Derek Muller explains the new research, published earlier this year in Nature Communications, that disproves longstanding beliefs about how chameleons change color. Previously, scientists thought that chameleons were able to change from green to yellow by dispersing different colored pigments through their skin cells. But instead, what researchers found was that all of chameleons' colors—their resting green and agitated yellows and oranges—are determined by changes in the way light reflects off the crystal structure of their cells. Check out the video above for a more detailed explanation.