Very interesting.

This explanation appears in Websters World Encyclopaedia: "An explanation of the custom of dressing boys and girls in different colours is linked with their sex. Babies all look alike, and what better means of identifying them readily than by colours ? blue for boys and pink for girls? This colour scheme has been adopted all over the world. But who would ever suspect that the blue ribbon is tied up in a terror-crazed past and a haunting fear of anxious parents, deeply concerned with their baby's future?