Pink/Blue - Baby Colors

So we were sitting watching the sunset today and I commented that it was nursery colors. Then of course, wife and I started discussing how bright pink and pale blue got associated with babies and then how each color got associated with a particular sex. The wine has kicked in and we are coming up clueless. Any ideas? Any ideas that might actually be true?

Thanks
gkj & wife (she used to just be co-applicant)

This was discussed in detail in an earlier thread: http://boards.straightdope.com/sdmb/showthread.php?threadid=32984