This is the same nonsubdued pin-on metal insignia worn by Colonels on the the shoulder loops of coats (AGSU, Windbreaker, All-Weather) and the sleeves of jackets (Blue or White Mess Dress).
Colonels and other officers were first authorized to wear pin-on metal insignia in 1942 on the Garrison Cap, which until 2001 was the standard headgear worn with the Class A Army Service uniform (commonly called “Army Greens”). An edict at that time by Army Chief of Staff Eric Shinseki replaced both the Garrison Cap and the Service Cap with the black beret, which previously had been worn exclusively by members of Army Ranger units. But the Garrison Cap was brought out of retirement—albeit in a different color than its predecessor—with the introduction of the Army Green Service Uniform in 2018.
Today, the nonsubdued, pin-on metal Colonel’s rank insignia is worn centered on the flash of both the clothing-bag issue black beret and the various colored organizational berets (Green, Maroon, Tan and Brown) worn by members of Special Forces, Airborne, Rangers, and Security Force Assistance units. On the Garrison Cap, the insignia is worn on the left side, centered vertically on the curtain and positioned one inch from the front crease.
More Army Colonel Insignias