With the introduction of the Army Green Service Uniform (AGSU) in 2018, the nonsubdued pin-on insignia of grade for Lieutenant Colonels—a silver oak leaf—is primarily worn the shoulder loops of the AGSU, but it is also worn on the shoulder loops of the Black or Green All-Weather Coat and the Black or Green Windbreaker.
DA PAM 670-1 specifies that the nonsubdued, pin-on grade insignia for Lieutenant Colonel worn on the AGSU be made with oxidized silver, and it is worn with the stem facing the outside shoulder seam.
While this metal insignia is also authorized for wear on the sleeves of the Blue Mess and White Mess dress jackets, most Lieutenant Colonels opt for embroidered or embroidered bullion versions (see "Embroidered Bullion Rank Insignia" link below) of the silver oak leaf insignia because it fits in more uniformly with the embroidered ornamentation on the sleeves of those jackets.
More Army Lieutenant Colonel Insignias