https://wccftech.com/microsoft-introduces-new-dark-mode-experiences-for-ios-13-and-android/

"Dark Mode experiences on iOS. The colors pop for legibility without overwhelming the darker feel."

Microsoft is finally bringing a Dark Mode to its Office and Outlook apps on Android, iOS, and web. Dark mode has remained one of the most wanted features for the past two years. It may have taken the Windows maker a little longer than others to get on board this trend, but it’s finally here and all because of “customer choice.”