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
T99 (camouflage) T99 (camouflage) T/99 is the designation of the camouflage pattern of the Danish Armed Forces desert combat uniform. It is a 3 colour camouflage pattern, similar in design to the Danish M/84 pattern. It is considered to be the desert counterpart of M/84, and consists of different colors better suited for arid climates. The uniform contains splotches of earthy red and dark green on a sand-coloured background. The first version of T/99 was trialled in 1999 and issued in 2000 to Danish personnel attached to the Standby High-Readiness Brigade for United Nations Operations. These service personnel were dispatched to Africa