What Is The Keyboard Shortcut To Invert Colors On A Mac?
The default keyboard shortcut for invert colors on a Mac was disabled in an earlier version of OS X / macOS. The best way to regain the shortcut it to set it yourself via the System Preferences. Once in System Preferences, go to the Keyboard panel, click on the Keyboard tab, and select Accessibility in the sidebar. Check the box next to "Invert Colors". You should then be able to use Control-Option-Command-8 as the shortcut or set your own shortcut by clicking on the key combination on the right.
Alternatively, you can push Command-Option-F5 to bring up an Accessibility dialog that will let you invert colors on your display.