World War I may have introduced camouflage, but World War II saw the emergence of camouflage uniforms — though few and far between. In large part, the uniforms were olive drab and plain green, lacking any actual camo. During the invasion of Normandy, select infantry units of U.S. Army soldiers donned HBT camouflage uniforms made from cotton that resembled the uniforms worn by German Waffen-SS soldiers. Since most American soldiers didn’t wear camo uniforms, “friendly fire” incidents rose in frequency as a result.
In the Pacific, a few U.S. Marine Corps units, including the Marine Raiders, wore reversible M1942 camouflage uniforms referred to as “frog suits” — one side was a greenish camo for jungle warfare, and the other side was tan for the beach environments frequented during the island-hopping campaigns. The Marines adopted a similar design called the frog pattern helmet cover during the Korean War. These camouflage uniforms were also used by Brigade 2506, who were issued the frog suits by the CIA during the failed Bay of Pigs invasion.