Chameleons are amazing color-changers, and scientists have just made a new discovery about their skin that explains how they manage this feat. The skin of the chameleon is filled with tiny crystals that change their spacing to reflect different colors of light.
Chameleons get part of their color from reflective crystal structures rather than pigments, which absorb light. Chameleons are not the only creatures that get their coloring from reflected light, though. Blue butterfly wings look blue because they have crystal structures that reflect mainly blue light. Likewise, green chameleons do not have green pigment in their skin. They have yellow pigment, and their skin crystals reflect blue light. This combination makes them look green.
While you may have heard that chameleons can change color to match any background, researcher Micheal Milinkovitch says this is not true. They actually use color to communicate with other chameleons. The panther chameleon is green when relaxed, and so it blends in with its leafy surroundings, and only the males change color. They will put on a color display when they encounter a female or when competing with another male. Then, their skin will turn from green to yellow-orange and the black areas also take on a red tinge. Watch here!
To learn more about the chameleon’s color-changing skills, researchers took tiny samples of skin from both relaxed panther chameleon males and fighting males. Using a powerful microscope, they saw that the space between the crystals got bigger in the agitated males, like they were stretched apart. Larger gaps between the crystals cause orange and red to be reflected.
The chameleon color-changing trick has inspired engineers to design artificial chameleon-like skin that changes color when stretched. In the future, this artificial skin might be attached to surfaces of buildings or bridges where tiny cracks could be detected by color change. And although chameleons don’t change color for camouflage, people and military vehicles might end up using chameleon-like skin for this very purpose!