Camouflage the peacock flounder, squid and octopus actively change their skin patterns and colours using special chromatophore cells to resemble their current background, or, as in most chameleons, for signalling. However, Smith's dwarf chameleon does use active colour change for camouflage. Each chromatophore contains pigment of only one colour. In fish and frogs, colour change is mediated by the type of chromatophores known as melanophores that contain dark pigment. A melanophore is star-shaped; it contains many small pigmented organelles which can be dispersed throughout the cell, or aggregated near its centre. When the pigmented organelles are dispersed, the cell makes a
Military camouflage with magnetic sensors. Horizontal coils around the whole or parts of the ship generate magnetic fields to "cancel out" distortions to the earth's magnetic field created by the ship. Ship camouflage was occasionally used in ancient times. Vegetius wrote in the 4th century that "Venetian blue" (bluish-green, like the sea) was used for camouflage in the years 56–54 BC during the Gallic Wars, when Julius Caesar sent his scout ships to gather intelligence along the coast of Britain. The bluish-green scout ships carried sailors and marines dressed in the same colour. The emphasis on hand-to-hand combat, and the short range