The history of blue/pink colors for boys/girls

[Phidippides]

To sum up this article, the division of pink for girls, blue for boys arose post-WWI and continued through the mid-60s, when feminism decided to tear down these gender constructions and advocate unisex colors.  When pre-natal sex determinations became available in the mid-1980s, gender-specific clothing was more on the rise as people started to shop for babies before they were born.

When Did Girls Start Wearing Pink?

This is interesting (to me, at least) because of the correlation between historical ideologies and changes in the material environment.

[Aetheling]

More about that shift

http://www.scribd.com/doc/25371458/Gender-References-for-Purple-Red-and-Blue
http://www.scribd.com/doc/46922192/Red-and-Blue-in-Architecture-and-Artwork p.3