Too Long; Didn't Read
Until the late 19th century, young boys and girls were traditionally dressed in white dresses until five or six years. Around the 1920s, magazines started to advertise pink for boys and blue for girls aggressively. The reason is that pink is a strong gender identifier, and blue is the default color for male babies. In the 1950s, the First Lady of the United States in the U.S. was fond of pink clothing that happened around the 70s – perhaps not pink, perhaps because pink, became more suitable for boys, and girls.