Green beret
The 10th Special Forces Group (Airborne) had many OSS World War II veterans in their ranks when it was formed in 1952. They began to unofficially wear a berets of varying colour while training. The color green became favored because it was reminiscent of the World War II British Commando-type beret. The 10th Special Forces Group (Airborne) deployed to Bad Tolz, Germany in September 1953. The remaining cadre at Fort Bragg formed the 77th Special Forces Group. Members of the 77th SFG began searching through their collections of berets and settled on the Rifle Green colour of the British Rifle Regiments (as opposed to the Lovat Green of the Commandos) from Captain Mike de la Pena's collection. Captain Frank Dallas had the new beret designed and produced in small numbers for the members of the Special Forces.
Military beret
Icelandic armed services commonly use berets.
The beret is the standard headgear for the Indian Army. Berets are worn by officers and other ranks, apart from Sikhs, who wear turbans. The beret colours worn by the Indian Army are as follows:The beret is the standard headgear of armed forces and police personnel in Indonesia. It is also worn by paramilitary and other uniformed services in the country such as the Fire Brigade, Search and Rescue, Scouts, civil militias (such as "Banser") and civil paramilitary organizations. In the Military Services (Army, Navy and Air Force), the berets are dragged to the right (the insignia are worn on the left side), while in the Indonesian National Police force and Military Police Corps, the berets are dragged to the left (the insignia are worn on the right side). Both having its own meaning, dragged to the right meaning "ready for combat and defense" and dragged to the left meaning "ready for law enforcement and order". 
Military and Police services according to their beret colours which represent different units within the force are as shown below:The beret color system used for the different branches of the Iraqi military and security forces changed after the fall of Saddam Hussein.
Beret colors currently (and formerly) worn by Iraqi forces are as follows: