Excited for Dark mode in macOS, but not ready to install the Mojave developer beta? You can enable an experimental version right now in High Sierra.
It’s called NSWindowDarkChocolate. It’s likely an experimental precursor to Dark Mode proper, and it’s not great: many applications don’t change at all when you enable it, and some, such as the Finder, only change partially, as seen above. Tab titles in Safari are basically unreadble. It’s not great, is what I’m saying, but if you’re desperate for dark it’s fun to play around with.
To enable this open the Terminal and run the following command:
defaults write -g NSWindowDarkChocolate -bool TRUE
Then log out of your account and log back in. You’ll find many windows are a lot darker.
To disable this—and you should disable it, because it is bad—run this command:
defaults write -g NSWindowDarkChocolate -bool FALSE
Reboot and your Mac will be back to normal.