Steele says pink was initially "considered slightly masculine as a diminutive of red," which was thought to be a "warlike" color.

However, the pastel shade has also long evoked "health (as 'in the pink') and youth." So writes Jo Paoletti in her book Pink and Blue: Telling the Boys from the Girls in America--one of the only books to examine the color's gender coding at length. "Young men and women might wear pink clothing; old men and women did not," Paoletti writes.

Paoletti says our great-great-great grandparents and their ancestors were more concerned about distinguishing children and babies from adults than boys from girls. "Pink and blue were suggested as interchangeable, gender-neutral nursery colors,' appearing together in many of the clothes and furnishings found in the baby's room"--similar to the hats hospitals often give to newborn.

By the late 19th century, however--and especially as Freud and other psychologists' theories of childhood development gained hold--parents began to differentiate their offspring's sex earlier on. As they did, some parents favored pink for girls and blue for boys, though Paoletti reports that wide variance continued for several more decades.

Steele says the French exerted an early, if modest, influence on pink's gender coding. Thus, as both she and Paoletti note, Louisa May Alcott's 1880 classic Little Women credits the French when Amy distinguishes her sister's newborn twins by giving the baby girl a pink ribbon, the baby boy blue.

For several decades, however, pink defied consensus. Based on a review of museum collections and other sources, Paoletti found pink baby gifts and even the occasional garment for boys or "baby brother paper dolls" into the 1960s, though "[t]hese examples are all clearly out of the mainstream. By the 1950s, pink was strongly associated with femininity."

Steele told me this view of pink was mainly "for young girls. ... It seems to be a kind of early gender coding that worked especially on young girls." As she wrote in her 1985 book Fashion and Eroticism, "The decade of the Fifties was characterized by an ideological emphasis on conformity, and by fashion images that were sharply age- and gender-specific."

Thus Betty Friedan rails repeatedly in The Feminine Mystique about the setbacks women experienced in the 1950s, compared to their gains and relative freedom in the two decades before.

Ironically, Paoletti thinks it was this very sort of feminist critique of mid-century gender roles that helped solidify the feminization of pink for girls and women. "Since the 1980s ... pink [has] become a strongly feminine color (probably because the women's movement connected it with traditional girliness so successfully)." As the turmoil of the 1960s gained strength, and young baby boomers began to question traditional gender roles, women embraced more "masculine" styles such as pants and short haircuts. For their part, men enjoyed the so-called Peacock Revolution, wearing their hair longer and more colorful garments.