Gendered associations of pink and blue

This restroom sign on an All Nippon Airways Boeing 767-300 uses pink for the female gender and blue for the male gender.

The colors pink and blue are associated with girls and boys respectively in large parts of the Western world.

Originating as a trend in the mid-19th century and applying primarily to clothing, gendered associations with pink and blue became more widespread from the 1950s onward. Since the 1990s, these gendered associations have also increasingly applied to toys as well, especially in the case of pink toys for girls. Additionally, the two colors are often used at gender reveal parties.

Various academic and popular sources have reported either a "pink–blue reversal", wherein the gendered associations of both colors were "flipped" sometime during the 20th century, or at least an inconsistency in the gendered application of colors prior to the mid-twentieth century, with several publications from the late 1800s to the early 1900s asserting pink being preferred for boys and blue for girls.