- Make sure that you have Light Mode enabled in System Preferences
- Open System Preferences on your Mac
- Tap General
- Under Appearance, select Light
- Open Terminal on your Mac
- Enter the following prompt into the command line:
defaults write -g NSRequiresAquaSystemAppearance -bool Yes
After you have entered the prompt above and hit Enter, you may be prompted to enter your password. Do so, and then hit Enter again. Here’s what you’ll need to do next:
- Tap the Apple logo in the top right of the Menu Bar
- At the bottom of the list, select Log Out
- After you have logged out of the computer, go ahead and log back in
Open System Preferences
- Tap General
- Under Appearance, select Dark
In the event that you are done experimenting with changing how macOS looks, you can revert it back. This makes it so that the entire Mac system is in Dark or Light mode when making the selection in System Preferences.
The System Preferences panel stays the same as it was when you had opted for Light Mode. But both the menu bar AND the dock are in dark mode!
defaults write -g NSRequiresAquaSystemAppearance -bool No
Source : https://appletoolbox.com/can-you-use-a-dark-menu-bar-and-dock-with-macos-catalina/
NSRequiresAquaSystemAppearance
can switch dark mode off per app, but I'm not sure it can switch it on.