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 were also painted in the same colour. At the same time, disruptive schemes using several colours were also tried out. By mid-1916 a silver-grey aluminium dope became the norm for Nieuports until the French introduced a standardized disruptive camouflage scheme for combat aircraft in 1917. This was used widely on such aircraft as the Breguet XIV and SPAD XIII that consisted of dark and light green, dark and light brown, black (sometimes omitted) and an underside of grey or beige. In mid-1916, the Germans experimented with a transparent cellon covering on several aircraft, including a Fokker E.III, that rendered the