jackets. Army personnel were also issued epaulettes that could be sewn to the old CF green service dress tunic to convert it into a "new" DEU tunic. The tan summer uniform was discontinued in the mid-1990s in favour of the green uniform to address complaints of soldiers needing to maintain multiple uniforms. Beginning in the 1990s, the peaked service cap was phased out for Army personnel with the exceptions of certain reserve regiments (e.g. Canadian Grenadier Guards), instructors of the Royal Regiment of Canadian Artillery School at Gagetown, and as an optional item for wear by general officers, with the beret (except in Scottish and Highland regiments) issued as the universal Army headgear for service dress. More recently, the heavy combat sweater was retired, replaced with a lighter-weight V-neck sweater for service dress wear, and with a fleece sweatshirt for operational wear. Air Force Personnel in the Air Force are issued a uniform of a similar cut to the old CF greens, but in blue, with a light-blue shirt, black necktie, and air force blue wedge cap. Air personnel were also issued a blue beret for wear when appropriate; it was soon authorized as was the blue flyer's jacket and Gore-Tex "line" jackets for use with work dress, then with service dress. When the blue uniform was introduced, the rank insignia and buttons retained the gold colour used by the CF greens. In 2015, this was changed to pearl grey rank insignia and silver buttons. Special Operations Forces In 2017 the Special Operations Forces Branch began to wear DEUs that are distinct from the Navy, Army, and Air Force. The uniform consists of a dark olive five-button jacket, light olive trousers bloused over black jump boots, light khaki shirt and olive tie, and a tan beret. Purple trades For military occupations that are not specifically designated to a particular environment (e.g. administrators, military police, medical personnel, etc.), an environment is usually assigned or may be requested on enrolment. Due to the way that members of these "purple trades" frequently have environments different from their current assignments, many units, when in ceremonial, service or mess dress, will display a mix of Navy, Army, and Air Force uniforms. As various specialty courses become more widely available, no longer restricted only to "soldiers" or "sailors", for example, it is not unheard-of to see a Navy HRA/FSA in a tactical air squadron with parachutist's