How do chameleon change colors?


THE chameleon is a unique animal which can change the color of their skin. Adult chameleons  range in size from four to 24 inches. These lizards belong to the taxonomic family of Chamaeleontidae. They are utterly defenseless. They can’t execute defensive bite, they do not have poisonous venom like snakes  and they can’t move away quickly from predators. Staying hidden is pretty much their only tactic to evade predators. Chameleons can rapidly change color by adjusting a layer of special cells nestled within their skin. The chameleons have two superposed crystal-like thick layers cells called iridophore cells underneath their skin. The iridescent cells have pigment and reflect light. These iridophores also have nano-crystals of different sizes, varying wavelengths. The chameleon changes its color by exciting or relaxing its skin, changing the density of the upper layer of iridophores. When they are excited or relaxing, these cells act like prisms, reflecting different wavelengths of light to create a variety of tones that we see.