At the beginning of World War I, the Air Force used the British flag, but it was easily confused with the iron cross symbol of the German Air Force in the air. So1October 19 14 began to adopt the original French concentric circle style, with red, white and blue colors from the center to the outside. A year later, the relative size of the ring was changed, and later a yellow ring was added during World War II. During World War II, the aircraft serving in the Far East removed the white circle on the logo to prevent confusion with Japanese aircraft. Since 1970s, airplanes that need camouflage have started to use the circular emblem with low visibility, red and blue are used for dark camouflage, and diluted pink and light blue are used for light camouflage. Most training and transport planes that do not need camouflage still maintain the traditional red, white and blue tricolor flag emblem.