Hey, I recently played this game and thought it was great, but there was one thing I couldn't quite figure out and have been unable to find any help with online, the Sisters quest.

I gather that one house with the colorful buttons that make various noises has something to do with it, but that's about as much as I've been able to figure out. Do I have to hit the buttons in a specific order? If so, how do I figure out that order, cause I've tried a few things that haven't seemed to work, some based on their colors and some based on the sounds they make.  Alternatively, do I actually have to meet the sisters elsewhere and then come to the house? If that's the case, where are they, cause I haven't found them. Or am I actually barking up the wrong tree entirely?

Anyway, thanks in advance to whoever answers (and I apologize if there's something super obvious I'm missing.)