I can't recall where I read that but back in the days blue was considered girl's color (because it is the color of some delicate flowers, not to mention sky), a

I can't recall where I read that but back in the days blue was considered girl's color (because it is the color of some delicate flowers, not to mention sky), and pink was considered boy's (because it's vauge resemblance of blood, preferably of his enemies slain in battle).