Active camouflage the surface, so when marine animals are seen from below, they appear darker than the background. Some species of cephalopod, such as the eye-flash squid and the firefly squid, produce light in photophores on their undersides to match the background. Bioluminescence is common among marine animals, so counterillumination may be widespread, though light has other functions, including attracting prey and signalling. Color change permits camouflage against different backgrounds. Many cephalopods including octopuses, cuttlefish, and squids, and some terrestrial amphibians and reptiles including chameleons and anoles can rapidly change color and pattern, though the major reasons for this include signalling, not
Aircraft camouflage 15mph (25kph) compared to glossy black, which, being smoother, produced less drag. Since, however, black camouflage made the planes conspicuous on moonlit nights and against cloud, a variation of a day camouflage scheme was eventually chosen. In the early years of World War II, German U-boats often escaped attack by aircraft because they spotted the aircraft while it was still far away as a black dot in the sky, no matter what camouflage colors were used. To solve this problem, in 1943 the U.S. Navy, following the Canadian diffused lighting camouflage trials on warships, conducted secret experiments on counter-illumination in