With the latest update of Microsoft Outlook for Mac (Version 16.20), I activated Dark Mode but, now that I've been using it for a while, I find it difficult to read my mails.
How can I switch back to normal mode? I didn't find an option to disable the dark mode in the UI.
In a command line, type:
defaults write com.microsoft.Outlook NSRequiresAquaSystemAppearance -bool yes
Credits: Is there a way to toggle Dark Mode on/off for individual apps in MacOs Mojave?