I use this setting often, together with Increase Contrast, through the Accessibility Shortcuts menu. For whatever reason, my computer feels more peaceful and calm with those on, even if it's worse and uglier too.

How did you assign it to a hotkey? I'm sure there's at least a dozen ways to do it, but I couldn't find a simple one without installing additional software.

I use the "Shortcut" section in Accessibility Settings. I uncheck everything except for "Color Filtering". I then map the default hotkey to a more convenient key using BetterTouchTool. BetterTouchTool is additional software for customizing input devices; I've used it for a decade and I consider it essential.

Sadly, adding "Increase Contrast" to the shortcut causes the hotkey press to generate a voiced popup instead of quietly and directly toggling.