Another way would be to modify the overall color settings:
- Menu "Tools" -> "Options"
- in options: "LibreOffice" -> "Application Colors"
- modify the very first color property "General" -> "Document background":

This will affect every document including writer and draw; it will affect every document independent from its source (assume working with a spreadsheet created by other people); and it won't affect other users working with your document (since it isn't a document / cell property but a user-specific application property). Of course, setting the cell background color manually or by using styles will override the general document background.