In 1954, the Warrant Officer Act, , created separate ranks for each pay grade, W-1 through W-4. On 10 September 1956, AR 670-5 authorized the approved insignia for the new ranks that consisted of a metal frame around a brown enamel bar. The insignia for warrant officer 1 (Grade W-1) and chief warrant officer 2 (Grade W-2) was a gold metal frame with one or two horizontal metal bands across it. Chief warrant officer 3 and chief warrant officer 4 had a silver frame with one or two horizontal bands across it.