We already have a treehouse that is more gender neutral but we specifically wanted a house that had a bathroom, kitchen, bedrooms etc and it had to have opening and closing doors and windows. So pink it was. I also don't care about pink and the boys like pink but it still irks me that we couldn't get a regular house colour (in a reasonable budget) without going DIY.
Treehouse sounds very cool Yes we were considering building one out of a bookcase, but are still working on their kitchen so weren't really up to the challenge!

Raffy we were hoping to get a pram for our guys and again they're all pink.