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
RAL colour standard relates to the shade of the colour: This collection, which follows the naming of RAL Classic, was invented in 1961. It is nowadays made up of ten colours (RAL 1039-F9 Sand beige, RAL 1040-F9 Clay beige, RAL 6031-F9 Bronze green, RAL 6040-F9-Light olive, RAL 7050-F9 Camouflage grey, RAL 8027-F9 Leather brown, RAL 8031-F9 Sand brown, RAL 9021-F9 Tar black and RAL 6031-HR Bronze green for non-camouflage applications), used by the "Bundeswehr" for military camouflage coating. In 1993 a new colour matching system was introduced, tailored to the needs of architects, designers and advertisers. It started with 1,688 colours and was