I've probably posted this, two, three times by now in various threads about the color pink, but traditionally, pink was always considered a boy color. Pink was seen to be a more powerful and bold a color than blue which was considered feminine and delicate. Even up until the early 1900s, pink was associated with boys, and blue for girls. The associations with both the colors only started to reverse around the mid 1900s.

So yeah. The colors themselves aren't exactly feminine or masculine. It's basically social conditioning that makes you associate one color for a particular gender.