The Royal Air Force uniform is the standardised military dress worn by members of the Royal Air Force. The predominant colours of Royal Air Force uniforms are blue-grey and Wedgwood blue. Many Commonwealth air forces' uniforms are also based on the RAF pattern, but with nationality shoulder flashes. The Royal Air Force Air Cadets wear similar uniforms. Current uniforms Official numbering The RAF currently numbers the various uniforms which may be worn. The following table summarises the numbering: Service dress The RAF's service dress is worn on formal and ceremonial occasions. In temperate regions, it is the most formal uniform in use at present. It remains essentially unchanged from the service dress uniform adopted in the early 1920s. It consists of a blue-grey jacket and trousers (or skirt for female personnel). A great coat may be worn at ceremonial events when the weather is cold. In warm weather regions a stone coloured variant of Service dress is worn. In 1947, the temperate officers' services dress jacket was altered. The lower side pockets were removed and the single slit was replaced by two hacking jacket style slits. The lower button was moved up to a position behind the belt and silk embroidery flying badges were replaced with ones in bullion embroidery. These changes were unpopular and in 1951, with the exception of the lower button move, the former uniform style was re-adopted. Service dress takes the following forms: No. 1 Service Dress, for temperate regions. Blue-grey colour. No. 1A Service Dress (Ceremonial Day Dress), for temperate regions and for air officers only. As per No. 1 Service Dress. Air vice-marshals and above wear a ceremonial sash and shoulder boards. Entitled air commodores only add the ceremonial sash. No. 6 Service Dress, for warm weather regions. Stone colour. Service working dress Service working dress, officially designated Number 2 Dress, is the routine uniform worn by most RAF personnel not on operations. It is analogous to the Army's barrack dress. RAF service working dress comes in a number of variations: No 2: Long sleeve shirt with jumper and tie No 2a: Long sleeve shirt with tie, jumper not worn No 2b: Short sleeve shirt without tie, jumper not worn No 2c: Long sleeve dark blue shirt without tie, jumper optional (engineering trades and cadets only) The RAF stable belt may be worn with all forms of service working dress. In warm weather regions