global-highlight-changes-mode

global-highlight-changes-mode is a variable defined in `hilit-chg.el'.
Its value is

nil

Documentation:
Non-nil if Global-Highlight-Changes mode is enabled.
See the command `global-highlight-changes-mode' for a description of this minor mode.
Setting this variable directly does not take effect;
either customize it (see the info node `Easy Customization')
or call the function `global-highlight-changes-mode'.

You can customize this variable.