It is the light reflecting cells in the skin that provide chameleon their uncanny color-changing abilities that help them attract mates and ward off predators .Unlike other animals that change color , such as the squid and Octopus , Chameleon do not modify their hues by accumulating or dispersing pigments within their skin cells. Instead the lizards rely on structural changes that affect how light reflects off their skin Researchers found that chameleons have two super posed thick layers of iridophores cells ,that have pigment and reflect light The iridophores cells contain nano crystals of different sizes , shape and organizations, key to the Chameleons' dramatic color shifts, according to researchers.The Chameleon change the structural arrangement of the cells by relaxing or exiting the ski