Berets of the United States Army
U.S. Army Special Forces wear the green beret because of their link to the British Commandos of World War II. The first Ranger unit, commonly known as Darby's Rangers, was formed in Northern Ireland during the summer of 1942. On completion of training at the Commando Training Depot at Achnacarry Castle in Scotland, those Rangers had the right to wear the British Commando green beret, but it was not part of the regulation uniform at the time and was disallowed by the U.S. Army. 
The 10th Special Forces Group (Airborne) had many veterans of World War II and Korea in its ranks when it was formed in 1952. Members of the 10th SFG began to unofficially wear a variety of berets while training, some favoring the red or maroon airborne beret, the black beret, or the green commando beret. In 1953, a beret whose design was based on that of the Canadian Army pattern, and which was rifle-green in color, was chosen for wear by Special Forces units.
Maroon beret
Headquarters, Department of the Army (HQDA) policy from 1973 through 1979 permitted local commanders to encourage morale-enhancing distinctions. Airborne forces chose to wear the maroon international parachute beret as a mark of distinction. However, due to the variety to headgear utilized at unit level, such as the Stetson being used in cavalry units, this permission was rescinded in 1979 when the army introduced a policy of standardized headgear. Exceptions were allowed for the continued wearing of the black beret (changed to tan in 2001) for the 75th Ranger Regiment & Ranger Training Brigade, and the green beret for Special Forces. On 28 November 1980 permission was given for airborne organizations to resume wearing the maroon beret. Most American paratroopers refer to it as a red beret, which history and tradition mandates, out of respect for their World War II British allies.
The Venezuelan National Guard is the fourth component of Venezuelan Army Force (Army, Navy, Air Force and National Guard), responsible for all military operations (Land, Air, Sea) that secure the public order including antidrug operation, administrative police (customs police and cooperation with SENIAT), external security of jail, public security, citizen security, environment police, and the cooperation with the army, navy and air force for military operations in the defense of the nation. They have one Unit of Special Forces (Grupo de Acciones de Comando) involving many military special operations alongside law enforcement duties. All personnel of the National Guard wear maroon berets.