Title: Full dress uniform
Content:  the Army introduced a blue service dress uniform, based on the full dress blue uniform. Presently, the Class A Army Service Uniform serves as the U.S. Army's equivalent to full dress. In November 2018, the U.S. Army announced the dress blue service uniform would be replaced by Army Green service uniforms. The U.S. Army intends to maintain the dress blue uniforms for ceremonial use. The U.S. Army's uniform regulations also define a class of "special ceremonial units," that are authorized to wear distinct ceremonial regimental uniforms for ceremonies and public duties. They include select U.S. Army band and guard units, including the 3rd Infantry Regiment's Commander-in-Chief's Guard, the First Troop Philadelphia City Cavalry, and some National Guard. Additionally, cadets at the United States Military Academy wear a cadet grey swallow-tailed blouse with white trousers and black shako for parades and drills.
Title: Service dress uniform
Content:  and black shoes. Women may wear a dark blue skirt instead of trousers. A peaked cap may be worn instead of the beret. The blue uniform's colours are based on the traditional colours used by most U.S. Army uniforms until 1902, when the introduction of khaki and olive drab uniforms relegated blue uniforms to full-dress use and off-duty wear until 1917, when issuance was halted due to the First World War. The current version of the uniform was reintroduced in 1957 as an optional full dress uniform. It was authorized as the army-wide service dress uniform in 2008, becoming standard-issue in 2010, when it replaced the previous green service uniform in use since 1954. With the reintroduction of a green service uniform, the blue uniform returns to being an optional uniform for more formal occasions.
Title: Full dress uniform
Content: Dress Blue "A" has a long sleeve choker-collar midnight blue outer blouse, white barracks cover, with all medals and service ribbons. Enlisted coats have a red trim and more buttons down the middle of the coat than officers. ; Dress Blue "B" is the same as "A", but service ribbons and marksmanship badges are worn instead of medals. Dress Blue "A" (with medals worn) is strictly reserved for official ceremonies, while Dress Blue "B" may be worn on leave or liberty. ; Dress Blue "C" is the dress blue uniform worn with the long sleeve khaki shirt (without coat). Service ribbons and badges may be worn. ; Dress Blue "D" is the dress 
Title: Full dress uniform
Content:  uniform worn with the short sleeve khaki shirt (without coat). Service ribbons and badges may be worn The most formal of a Marine's uniforms outside of the elaborate evening dress uniforms of officers and senior enlisted, it is often referred to as "Dress Blues", due to its color (as distinguished from the green and khaki service uniforms), and can be worn in many forms. It is the only uniform of the United States military to use all of the colors of the nation's flag and incorporates button designs which are the oldest military insignia still in use in the United States Armed Forces to this day. The various designations used in Dress 
Title: Full dress uniform
Content:  Prior to the 20th century, the uniforms of the United States Army were primarily made out of a combination of dark blue wool (for tunics or coats) and light blue (for trousers and breeches). After the adoption of olive drab and khaki uniforms in 1902, the US Army retained blue uniforms as its full dress until 1917. The blue full dress ceremonial overcoat was reintroduced in January 1929, and saw alterations to its design in 1936 and 1937, before it was suspended from use in 1943. The overcoat was reauthorized for use by officers in 1947, although it seldom sees use. The ceremonial overcoat with a white scarf is presently listed as an optional purchase item in the Army's uniform regulations, with general officers, aides-de-camp, and command sergeants major being authorized to wear it in formal ceremonial occasions during cold-weather conditions. In 
Title: Service dress uniform
Content:  The United States Army authorizes the Army Service Uniform as its daily wear service uniform. Since 2018, there are two versions authorized, a green uniform and a blue one. In November 2018, the U.S. Army announced the introduction of a new green service uniform modeled after the "pinks and greens" service uniforms worn by officers during the Second World War and Korean War. This uniform consists of a dark olive drab coat with belted waist, light taupe trousers, tan shirt, olive necktie, olive garrison cap, and brown shoes. A peaked cap is optional. This uniform became standard-issue beginning in 2020 and becomes mandatory in 2027. The blue service uniform consists of a dark blue coat, light blue trousers (dark blue for general officers), a white turndown-collar shirt, black necktie (neck tab for women), a black 
Title: Uniforms of the United States Marine Corps
Content:  The Marine Corps dress uniform is an elaborate uniform worn for formal or ceremonial occasions. Its basic form of a blue jacket with red trim dates back to the 19th century. It is the only U.S. military uniform that incorporates all three colors of the U.S. flag. There are three different variations of the Dress uniform: Evening Dress, Blue Dress, and Blue-White Dress; only officers and staff non-commissioned officers (SNCOs) are authorized to wear the Evening Dress. Until 2000, there was a White Dress uniform, similar in appearance to the U.S. Navy's Dress White uniforms, but worn by officers only (in a manner similar to that of the Dress White uniforms worn in the U.S. Coast Guard). This uniform has since been replaced with the Blue/White Dress uniform for officers and SNCOs.
Title: Uniforms of the United States Marine Corps
Content:  "D" is the same as "C", but with a khaki short sleeve shirt and no tie. The most recognizable uniform of the Marine Corps is the Blue Dress uniform, often seen in recruiting advertisements. It is often called Dress Blues or simply Blues. It is equivalent in formality and use to civilian black tie. The various designations are listed in descending order of formality: Because the Blue Dress uniform is considered formal wear, Blue Dress "C" and "D" are rarely worn. The main exceptions are Marine recruiters and Marine Security Guards, who wear the "C" and "D" in warm weather, and Marine One pilots in place of a flight suit. Only the "B", "C", and "D" Blue Dress uniforms are authorized for leave and 
Title: Uniforms of the United States Army
Content:  The current garrison service uniform is known as the "Army Green Service Uniform". Introduced in late 2018, it is based on the "pinks and greens" officers' service uniform worn in World War II and the Korean War. The service uniform includes a dark olive drab coat, light drab trousers, a khaki shirt, an olive drab tie, and brown leather shoes for both men and women, with women having the option to wear a pencil skirt and pumps instead. The uniform became available to soldiers in mid-2020. From 2010 to 2020, a blue uniform was used as the daily wear service uniform. The Army has a tradition of blue uniforms dating to the Revolutionary War, and the blue uniform returns to its previous position as a formal dress and ceremonial uniform. It had replaced in daily wear the previous green service uniform used by all officers and enlisted personnel introduced in 1956.
Title: Uniforms of the Royal Air Force
Content:  War service dress, also known as battle dress, was introduced in 1940 as a blue/grey version of the British Army's battle dress. Initially, war service dress was only worn by air crew. However, in 1943, its use was authorised for all ranks and trades. War service dress continued to be worn after the end of World War II. It was significantly altered in 1948 and not phased out until 1976.

Question: when do you get your dress blues in the army?
Answer: during initial entry training.
when commissioned.