“Little Franklin Delano Roosevelt, age two and a half, sits primly on a stool, his white skirt spread smoothly over his lap, his hands clasping a hat trimmed with a marabou feather.  Shoulder-length hair and patent leather party shoes complete the ensemble.
“We find the look unsettling today, yet social convention of 1884 dictated that boys wore dresses until age 6 or 7, also the time of their first haircut.  Franklin’s outfit was considered gender-neutral.”  —Smithsonian Magazine
For a long time, babies and toddlers were dressed in white—bleachable and therefore practical.  Colors—pink, blue and other pastel colors—arrived in mid-19th century.  It comes as a surprise to some people that, in 1918, you would have dressed your boy in pink and your girl in blue. The reason given was that pink, being a stronger color, was more suitable for the boy, while delicate and dainty blue was prettier for the girl.
In 1927, a Time Magazine article identified gender-appropriate colors for girls and boys based on the opinions of leading US retailers, Filene’s in Boston, Best & Co. in NY City, and Marshall Field in Chicago.  All told parents to dress boys in pink, girls in blue.  “Today’s color dictate wasn’t established until the 1940s” says the author of the Smithsonian article, “It could have gone the other way.”  It became unthinkable to dress your son in pink; to dress your daughter in blue was to invite compliments on your handsome little boy.
In the mid-1960s, the unisex look was in as baby boomers feared that their daughters might be lured by frilly dresses into an overly passive role in society.  For two years Sears Roebuck pictured no pink toddler wear.
But the pendulum swings and some young mothers who were dressed in gender-neutral clothing and deprived of Barbies see things in a different light according to the author of the Smithsonian article. “They think even if they want their girl to be a surgeon,” he writes, “there’s nothing wrong if she is a very feminine surgeon.”