The term "dress blues" refers to a military uniform worn for formal occasions. The dress blues uniform is worn by various branches of the military, including the Army, Marine Corps, Navy, and The ultra rare Marine Corps dress uniform accessory you may never see Historic uniform change for female Marines; 'there will be no doubts that they are U.S. Marines in the dress blue uniform' USMC MALE ENLISTED BLUE DRESS BLUE WHITE DRESS UNIFORM ("A" AND "B")