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
Middle East Command Camouflage Directorate bombs being dropped on wooden railways by an undeceived enemy. Barkas noted that "camouflage men must be among the few otherwise sane beings who yearn to be bombed." The pioneering effort's success was achieved in a few weeks, amidst severe shortages of men and raw materials. The writer Julian Trevelyan recorded that During the Eighth Army's retreat across Libya in 1941, the camouflage officer and former film art director Peter Proud and the camouflage sergeant William Murray Dixon found themselves trapped in the port city of Tobruk. Proud quickly set up a camouflage unit, acquiring a section of Australian engineers,