How to enable Yosemite's hidden dark mode | Cult of Mac

How to enable Yosemite’s hidden dark mode


Step away from the light with Yosemite's dark mode. Photo: Buster Hein/Cult of Mac
Step away from the light with Yosemite's dark mode, photo Buster Hein

OS X Yosemite is the biggest visual overhaul Apple’s made to the Mac in years, but developers at WWDC seemed most excited about one tiny UI tweak – dark mode.

Beta testers eager to try out the the new OS X 10.10 feature were disappointed to find out it didn’t make it into the first Yosemite beta, but our friend Jean-David Gadina, from the DiskAid developers team, has done some digging into the OS X Yosemite beta and discovered a new file not present in Mavericks that can be manipulated to enable the hidden dark mode feature.

Here’s how to do it:


  • Open your /System/Library folder by clicking Go >> Computer on the Apple menu bar, click your Yosemite drive then go to System >> Library
  • Open the CoreServices folder
  • Right click SystemAppearance.bundle and choose Show Package Contents
  • Open Content >> Resources
  • Rename “” to “”
  • Open System Preference >> General
  • Under Appearance switch from Blue to Graphite
  • Logout and log back in

Jean-David notes that the dark theme is clearly not finished – hence its omission from the first Yosemite beta. A lot of stuff is missing in the dark interface so only a few controls get the new dark look, while windows and menus keep the default light grey background.

However, the file is very interesting because it uses the same system as the one used in iOS 7 & 8, which should allow people to build their own “.car” theme files in the future.

For those wondering about the .CAR files, they contain definitions for the appearance of all UI elements of OS X. According to Jean-David’s research, it looks like they are built by the “distiller” utility Apple added in Mavericks, that can be found in a private framework called “CoreThemeDefinition.”

Once you’ve had your fill of partial darkness, revert back to the Blue appearance and fix the .car file names to their original state.

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