Dark Mode is a feature that some OS X users have wanted for a long time. Even those of us who wanted it may not want to live with it all the time, however. That's why there's a secret way to toggle it.
Ordinarily you need to open the System Preferences and click on the General preference to toggle Dark Mode (you check the preference that says "Use dark menu bar and Dock"). Three clicks and you're done. OK, it isn't that big a deal. But it's still cumbersome, especially if you're like me and you like to keep your fingers on the keyboard as much as possible.
By default, OS X doesn't offer any command-key shortcut to activate Dark Mode. But there's a command you can enter in the Terminal that, run once, will activate Dark Mode with a key command. Each time you want to toggle Dark Mode on or off, you simply hold down the command, option and control keys together, and then hit T.
How to activate Dark Mode using command keys
- Make sure all documents in other apps are saved and that other apps are closed, because you should restart your Mac at the end of this.
- Open Terminal.
- Type sudo defaults write /Library/Preferences/.GlobalPreferences.plist _HIEnableThemeSwitchHotKey -bool true (you can copy and paste this into your Terminal command line if you prefer).
- Because you're entering a "sudo" command, OS X will prompt you to enter your administrator password. Enter it and hit return.
- Quit the Terminal app.
- Restart your Mac.
Once your Mac has restarted, that hotkey sequence — command, option, control and T — will toggle Dark Mode on or off.
If you ever want to restore the normal behavior of OS X and prevent the Dark Mode toggle from working again, go ahead and launch Terminal again, then enter that same line above, but change the "true" at the end to "false."