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 he quickly pulled the painted canvas away and delivered a full broadside, capturing the enemy. In the American Civil War, camouflage paint was applied by both sides during the Union blockade of 1861–1865. Blockade runners aiding the Confederates sometimes painted their ships all in mist-gray, to hide themselves in coastal fog. One Union blockade crew may have painted their rowboat white, and its oars, and wore white clothing for a night reconnaissance patrol up an enemy-held river. In the 1890s, German and French fighting ships were being painted gray. American interest in ship camouflage was given official funding in 1898