U.S. Air Force combat uniforms have continuously evolved since the Air Force became an independent service in 1947. Until the late 2000s, USAF combat uniforms were the same as those of the U.S. Army, with the exception of unique USAF insignia. The fatigue uniform differed from its Army counterpart with white lettering on an ultramarine blue background for "U.S. AIR FORCE" and last name tapes above the pockets, white-collar rank insignia on a blue background for officers (with the exception of yellow thread replicating gold for rank insignia for 2nd Lieutenants and Majors) and blue and white sleeve rank insignia for enlisted, a full color patch of the major command (i.e., SAC, TAC, MAC, ATC, etc.) worn on the right pocket, and a blue belt.