To switch to the dark mode setting in the Outlook app on Windows, you need to change the app theme to black. Here’s how to do it (via Microsoft support):
- Launch the Outlook application on your computer.
- Click the File tab in the upper left corner of the screen.
- Go to “Office Account” at the bottom left of the sidebar.
- Under “Office Theme,” choose Black. You can also select Dark Gray if you prefer a lighter shade.
Your Outlook app, along with the rest of your Microsoft 365 apps, will automatically switch to the new theme. If you want your message window to remain blank while using the Dark theme, you can click the sun icon next to “Reply” at the top right of the message.
This will change the background of the message window to white. To darken the message window again, click the moon icon.
For Mac users with a Microsoft 365 or 2019 subscription, the process of enabling dark mode in Outlook is much simpler. All you need to do is set the app appearance to Dark. First, open your Outlook. Click on Outlook in the upper left corner next to the Apple logo. select Preferences > General and choose Dark in the Appearance row. Then just close the Preferences window.