And red used to be they "boy colour" while blue was the same for girls. Because blue is a calm colour while red is much more "manly and agressive." Customs change and for the record: making toys as gender oriented as western culture has is a "relatively" new thing if I've understood correctly.
Not that there wouldn't have always been some girl toys and boy toys, but these days some people seem to get into panic if a child is playing with "wrong" toys and I get the impression that things weren't always so strict.