By default the LyX background color is FAF0E6 (or 250, 240, 230).
I can change it by going to Tools > Preferences > Look & Feel > Colors > Background > "Alter..."
However, this changes the background color for all LyX documents.
Q: Is there any way I can change the color just for one specific LyX document and keep it the same for all others?
The reason is that I want to make it clear (to myself) which document is which, through distinct background colors.