<Tr> <Th> Variants </Th> <Td> OCP ACU, MultiCam ACU, UCP - D ACU, UCP ACU, Flame - Resistant ACU (FRACU) </Td> </Tr> <P> The Army Combat Uniform (ACU) and its flame - retardant variant, the Flame - Resistant Army Combat Uniform (FRACU), are the current battle uniforms worn by the United States Army . The ACU is also worn by some units of the U.S. Air Force and U.S. Navy, such as SEALs and navy sailors assigned to army units . </P> <P> First unveiled in June 2004, it is the successor to the Battle Dress Uniform (BDU) and Desert Camouflage Uniform (DCU) worn from the 1980s and 1990s through the early 2000s, respectively . The ACU and its component materials are manufactured by the existing industrial infrastructure which produced the now - obsolete BDU . Official military - grade ACUs are made of 50% nylon and 50% cotton . All other blends are not official issue . </P> <P> The ACU originally used the Universal Camouflage Pattern (UCP), which used a pixelated pattern of tan, gray and green (Desert Sand 500, Urban Gray 501 and Foliage Green 502) and was intended to work equally in desert, woodland, and urban environments . It is aesthetically similar to the USMC's MARPAT and Canadian CADPAT camouflage scheme on which it was based . The shade black was omitted from the uniform since it is highly visible both to the naked eye and to modern optics . Pure black, when viewed through night vision devices, appears excessively dark and creates an undesirable high - contrast image . The pattern proved to be ineffective in certain environments, and is thus scheduled to be fully phased out by 30 September 2019 . </P>

When did the army switch from bdu to acu