My girl picked herself a blue potty a few months back and I was happy with her choice. She's never been particularly girly and doesn't favour pink things or fairies / princesses but equally she isn't immune to a build a bear toy...meet Twilight Sparkle - an explosion of colour and frills (in the middle if you hadn't guessed!!)
So when we went and got another potty to use upstairs (she claimed the one before was uncomfortable...or rather another way to get out of using it). She chose a pink one, which again I had no strong views on.
That's until she had the option of using both at home and picked the pink one, claiming 'pink is for girls and blue is for daddy'. It's weird (but I guess unsurprising) that gender stereotyping starts this young. But it's not something that we have consciously taught her. Even kinder eggs have gone pink and blue which makes me sad...my girl loves a toy regardless and shouldn't have to choose between a boy or girl toy.