I've been talking to my buddy Jimmy at the Bike Line about this very subject for a couple years now. I fell in love with a lava red women's pilot 1.2 and there was no way I was going to be able to purchase it at that time, but when the next season's bikes came in nearly ALL the bikes were pastel (not the word I actually used to describe them but it'll do). The last couple of seasons they have continued the trend.
I've also talked to another buddy at the shop and he told me that he didn't understand it either. He said that nearly all the adult women who came in looking for a bike had the same reactions. It appears that some of the bikes are finally coming around for this season, but it stinks that you might need to go to either a high end bike or men's model to avoid the pastels.