List of historical sources for pink and blue as gender signifiers
Since at least the 19th century, the colors pink and blue have been used as gender signifiers, particularly for infants and young children. The current tradition in the United States (and an unknown number of other countries) is "pink for girls, blue for boys". Prior to 1940, two conflicting traditions coexisted in the U.S., the current tradition, and its opposite, i.e., "blue for girls, pink for boys". This was noted by Paoletti (1987, 1997, 2012). Since the 1980s, Paoletti's research has been misinterpreted and has evolved into an  urban legend: that there was a full reversal in 1940, prior to which the only tradition observed was the opposite of the current one. Quoting the concluding lines of this study: "In conclusion, there are strong reasons to doubt the validity of the standard PBR account; if anything, gender-color associations seem to be much more stable than currently believed" Key to tables. Year = year of publication Location = place to which text pertains Comments = brief quote from original text