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
Aircraft camouflage aircraft nearly invisible from most angles, however the sun reflecting off it defeated it even before its lack of durability did. When the Germans fielded the Albatros D.III sesquiplane, its similarity from a distance caused them to be confused for Nieuports, both of which used the same combination of colours to match the terrain they were operating over. Additionally, the Nieuports lacked overwing roundels and the German crosses were not always easy to identify. The solution the Germans came up with was to replace the red-brown with purple, which from a distance still worked well as a camouflage colour, but