Mac OS X doesn’t come with its own proper dark mode, but a developer has come up with a bit of a hack-ey dark mode theme that may be decent enough for most people to use.
With OS X Yosemite, Apple introduced the ability to use a dark Dock, Spotlight search, and menu bar. Many blogs called this a “dark mode” for OS X, which I always felt was quite inaccurate. A true dark mode for Mac OS X would darken the entire interface, including third-party applications.
Except for Windows Phone and a recent dark mode in Windows 10, no other platform offers such a feature. It makes sense because it’s fairly difficult to implement this across the entire platform without breaking the interface. Windows is only able to do it because their native theming libraries are designed with dark mode in mind.
Doctor Dark Mode Theme
So yes, I was pleasantly surprised when I came across a dark mode theme for OS X that promised a low-contrast interface throughout the operating system, including third party apps!
Have a look at it.
Dark Mode theme in Messages for OS X
Dark Mode theme in System Preferences
Dark Mode theme in console
Dark Mode theme in Mail
It doesn’t look spectacular, certainly. I’m a greater fan of the dark mode that comes in Windows. That is more uniform, and doesn’t have random white bits in the interface.
However, you have to understand that this is a indie developer effort. It comes from w0lfschild on reddit. They used SIMBL to patch third-party apps. The result is a pretty basic dark mode for macOS that works decently, but that’s just it. No more, no less.
To use the dark mode on your Mac, you need to download and install mySIMBL, Doctor Dark (the dark mode theme), and set them up. Once activated, you need to restart your Mac. Doctor Dark works on El Capitan and is expected to work on macOS Sierra, too.
I personally am not a fan of the theme. I am annoyed by its lack of consistency across the system. It leaves much to be desired.
You can find the complete instructions over on the original post on reddit.