How do chameleons change color?

Chameleons change color by adjusting specialized skin cells called iridophores, which contain tiny crystals that reflect light. These cells are located beneath their outer skin and can manipulate how light interacts with their body. When a chameleon wants to change color, it alters the spacing of these nanocrystals, which changes how they reflect different wavelengths of light. For example, when the crystals are close together, they reflect blue and green light, making the chameleon appear green. When they spread apart, they reflect red, yellow, or orange, changing the chameleon's color. Chameleons don’t just change color for camouflage; they also do it to regulate body temperature (darker colors absorb more heat) and communicate with other chameleons. For instance, a bright color can signal dominance or aggression, while a dull shade may indicate stress or submission.