&gt; I know you can invert colors in OSX but the effect is desktop-wide and you can&#x27;t use a hotkey to enable or disable it.<p>I haven&#x27;t tried this myself, but I believe you could rig up something in Automator&#x2F;Script Editor to toggle the inverted colors, then set up a hotkey for that service from System Preferences -&gt; Keyboard -&gt; Shortcuts.