 The principle of varying coloration either rapidly or with the changing seasons has military applications . Active camouflage could in theory make use of both dynamic colour change and counterillumination . Simple techniques such as changing uniforms and repainting vehicles for winter have been in use since the Second World War . In 2011 , BAE Systems announced their <unk> infrared camouflage technology . It uses about 1000 hexagonal panels to cover the sides of a tank . The panels are heated and cooled to match either the vehicle 's surroundings ( crypsis ) , or an object such as a car ( mimesis ) , when viewed in infrared . 
