I think blue was used to ward off evil spirits and keep the baby boy healthy.
I guess girls couldn't share the protection? :P
But then pink was maybe a flower color and we got that..who knows...about pink but I'm pretty sure on blue :)
let me get a link :P oh wait, I look wrong -thank you book from 7th grade drama teacher class-
here are some links link link link
:) and these all back each other up