Chameleon turquoise, and purple. Chameleon skin has a superficial layer which contains pigments, and under the layer are cells with guanine crystals. Chameleons change colour by changing the space between the guanine crystals, which changes the wavelength of light reflected off the crystals which changes the colour of the skin. Colour change in chameleons has functions in camouflage, but most commonly in social signaling and in reactions to temperature and other conditions. The relative importance of these functions varies with the circumstances, as well as the species. Colour change signals a chameleon's physiological condition and intentions to other chameleons. Chameleons tend
Ship camouflage was applied to other destroyers, a few cruisers, and numerous small warships which maintained the scheme through 1944 for use in coastal waters. No Admiralty camouflage section was established until October 1940. Admiralty camouflage schemes promulgated in 1941 were not universally adopted because of difficulties with operating schedules and shortages of some paint pigments. Nearly all destroyers and larger ships wore an Admiralty disruptive camouflage scheme by late 1942; but Commonwealth captains executed official camouflage schemes with greater variation than was customary with American measures. Initial Admiralty disruptive camouflage schemes employed polygons of varying shades of gray, blue and green