The 4th quadrant of a rainbow of three bands red, yellow and blue, each 3/8 inch (.95 cm) in width, outer radius 2 inches (5.08 cm); all within a 1/8 inch (.32 cm) Army green border.
The 42d Infantry Division is known as the "Rainbow Division" because personnel from 26 states originally formed the Division.
The shoulder sleeve insignia was originally approved by telegram for the 42d Division on 29 October 1918. It was officially authorized for wear in the United States by the War Department on 27 May 1922. The insignia was redesignated for the 42d Infantry Division on 8 September 1947. It was amended to include an Army green border on 24 March 1966. (TIOH Drawing Number A-1-106)