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
Military camouflage remained simple two-colour schemes (different upper and under sides) or even dispensed with camouflage altogether. Italian and some Japanese aircraft wore sprayed-on spotted patterns. German aircraft mostly used an angular splint-pattern camouflage, but Germany experimented with different schemes, particularly in the later stages of the war. They also experimented with various spray-on camouflage patterns for tanks and other vehicles, while Allied vehicles remained largely uni-coloured. As they had volunteered in the first World War, women sewed camouflage netting, organizing formalized groups for the work in Australia, Britain, New Zealand and the United States who took part as camoufleurs during the