How to change background color from blue to white.

I've spent half an hour looking through the 2024 user manual to find out how to change the background color without success. In videos for the 2017 version it looks easy, but those tools either aren't available or are now buried within others and I can't find them.

Does anybody know how to change the background color in a completed cut and fill project so I can copy and display it with a white background?