If you prefer the look of apps that use a Dark Theme, Windows comes with one that’s almost complete but isn’t 100%. If you’re okay living that close to the edge, you can Enable it now.

You can either download the Registry entry and merge it, or make the edit yourself.

Before you start, review this guide if you’re unfamiliar with editing the Windows registry.

To make the edit yourself:

1. Open the registry editor and navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Themes
2. Create a new key named Personalize
3. Within the key, create a new DWORD (32-bit) value named AppsUseLightTheme with a value of 0
4. Navigate to:
   HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Themes
5. If it doesn’t already exist, create a new key named Personalize
6. Create the same DWORD (32-bit) value named AppsUseLightTheme with a value of 0
7. Sign out of Windows and sign back in

To switch back to the light theme, delete the registry entries and sign out and back in. If you’d like to enable this for multiple users, sign in as that user and make the same change under HKCU (read more about the registry root keys.)

Want to customize Windows 10 further? See this tip and others like it here: Unlock secret settings in Windows 10