How to Invert Color on Mac running Catalina?
I can only use the keyboard shortcut if I go into System Preferences and explicitly unckeck and re-check the box for Invert Colors.  Once I am done with my session I enable screen saver by going to a designated not corner.  When I come back, the keyboard shortcut only produces the system sound for an alert without inverting the colors.  It is again only when I go back into System Preferences and uncheck/re-check Invert Colors will it work again.  This is highly annoying and frustrating as I rely on this for various apps that do not have a dark mode in my normal daily workflow.