The U.S. Marines in World War I Part I USMC Marine Corps Dress Blues Uniform Grouping (WW2 through Vietnam) Did you know? The Marine Corps' Dress Blues is the only uniform in the U.S. military designated to include the red, white, and blue colors of the American flag. This distinctive uniform A colorized photo of a US Marine in Blue Dress uniform, circa 1917 : r USMC Sergeant and Trumpeter, USMC WW1 era USMC dress blue tunic. : r USMC