I want to change the background color on some cells based on whether a checkbox is clicked on another cell. I also want to protect these same cells from being edited so I have protected these cells (not the cell with the checkbox). Can I use conditional formatting on protected cells in LibreOffice Calc? (I can do this with Google Sheets.)
Of course, you can. If you use a checkbox to change the value of the referred cell, this cell may also be protected.
Cell protection protects against editing. It does not block changes by recalculation or by running code.
See example: ask288726sheetProtectionAndValueChanges.ods