Berets were introduced initially into the Royal Tank Corps in the First World War and their use became more widespread in the British Army during and after the Second World War to replace side caps for wear with combat uniforms when protective headgear was not being worn. Originally, khaki was the standard colour for all units, but specialist units adopted coloured berets to distinguish themselves. For example, airborne forces adopted a maroon. This has since been adopted by many other parachute units around the world. The Commandos adopted a green beret. The Special Air Service (SAS) initially adopted a white beret quickly changing this to a beige or sand coloured one. From 1944 they wore the Maroon airborne forces beret but the beige beret was re-adopted following the re-formation of the Regular SAS in Malaya.