In Microsoft Excel a cell’s fill color/background color is set by default with Theme and Tint attributes, whereas in LibreCalc it is ‘Standard’/RGB hexadecimal.
I tried, Left Click on Cell > Navigate to Format> Cells, then Font Tab.
There’s only option to change font name/style, the size. I tried Background tab> Color button, I see a drop down menu with Standard set to default. I plan to use OpenPyxl to hopefully get and set the tint and theme values.
The page here:
https://help.libreoffice.org/latest/en-US/text/shared/01/themescolordialog.html
Says Format> Theme
Theme does not appear under Format. I only see Spredsheet Theme which affects all cells.