Boys and girls used to wear white dresses (yes, even the boys) until age six or seven when they got their first hair cut. Then…

The march toward gender-specific clothes was neither linear nor rapid. Pink and blue arrived, along with other pastels, as colors for babies in the mid-19th century, yet the two colors were not promoted as gender signifiers until just before World War I—and even then, it took time for popular culture to sort things out.

For example, a Ladies’ Home Journal article in June 1918 said, “The generally accepted rule is pink for the boys, and blue for the girls. The reason is that pink, being a more decided and stronger color, is more suitable for the boy, while blue, which is more delicate and dainty, is prettier for the girl.” Other sources said blue was flattering for blonds, pink for brunettes; or blue was for blue-eyed babies, pink for brown-eyed babies, according to Paoletti.

In 1927, Time magazine printed a chart showing sex-appropriate colors for girls and boys according to leading U.S. stores. In Boston, Filene’s told parents to dress boys in pink. So did Best Co. in New York City, Halle’s in Cleveland and Marshall Field in Chicago.

Today’s color dictate wasn’t established until the 1940s, as a result of Americans’ preferences as interpreted by manufacturers and retailers. “It could have gone the other way,” Paoletti says.

So the baby boomers were raised in gender-specific clothing. Boys dressed like their fathers, girls like their mothers. Girls had to wear dresses to school, though unadorned styles and tomboy play clothes were acceptable.

via When Did Girls Start Wearing Pink? | Arts & Culture | Smithsonian Magazine.