The same thing happened to me. I am so frustrated. I can't figure out how to call Squarespace and talk to someone. Everything is black except for photos.
I am glad to know it isn't just me. I just changed it again to white and then it went back to being a black background. I was trying to figure out how to call squarespace for technical support and I can't figure out how to get a hold of someone. So frustrating!
I had a white background on my Squarespace website. It randomly changed to a black background. I have tried changing the color in the formatting, and it won't change back. Is this some sitewide Squarespace error?