According to Nature Communications, new research shows chameleons by stretching or relaxing its skin, actively tune nano-crystals to change their color.
“It is generally interpreted that these changes are due to dispersion/aggregation of pigment-containing organelles within dermal chromatophores.”
The research was carried out by Jérémie Teyssier, Suzanne V. Saenko, Dirk van der Marel & Michel C. Milinkovitch at the University of Geneva Department of Quantum Matter Physics and the Laboratory of Artificial and Natural Evolution (LANE).
From the article “Photonic Crystals Cause Active Colour Change in Chameleons” by J. Teyssier, S.V. Saenko, D. van der Marel & M.C. Milinkovitch.
Nature Communications (2015).