Displays cell content in different colours, depending on type.
To remove the highlighting, unmark the menu entry.
Choose View - Value Highlighting.
By default:
Text cells are formatted in black, formulae in green, number cells in blue, and protected cells are shown with light grey background, no matter how their display is formatted.
These colours can be customised in Tools - Options - Office - Application Colours.
If this function is active, colours that you define in the document will not be displayed. When you deactivate the function, the user-defined colours are displayed again.