The default theme for Microsoft 365 is Use system setting, which matches the Windows theme. You can change the look and feel of all your Microsoft 365 apps by changing the theme or background.
How to change your theme
To change the background color and design of all your Microsoft 365 apps:
Open a Microsoft 365 app, like Word, Excel, or PowerPoint.
In the top left, select File > Options > General > Office Theme.
Choose one of the options.
The colorful theme aligns with the visuals of our modern Microsoft 365 apps by bringing their primary accent color to the ribbon.
The colorful theme in Excel:
The colorful theme in PowerPoint:
The colorful theme in Word:
Dark gray theme
The dark gray theme is perfect for those who prefer a softer take on high-contrast visuals. Here's an example of the dark gray theme applied to PowerPoint:
The Black theme provides the highest-contrast visual for your Microsoft 365 apps. Here's an example of the black theme applied to PowerPoint:
The white theme displays the classic look of Microsoft 365. Here's an example of the white theme in PowerPoint:
On the Mac, Microsoft 365 apps will match the Light or Dark appearance of your Mac.
Tip: If you would like your Microsoft 365 apps to always use a Light appearance regardless of your Mac settings, you can enable "Turn Off Dark Mode" in Microsoft apps.
If you are a Microsoft 365 subscriber, you can also choose between two themes when your Mac is using a Light appearance.
To change the theme, click on the menu for your Microsoft 365 application (Word, Excel, etc.) and select Preferences > General. Under the Personalize section you can configure your theme.
Aluminum theme (default)
The Aluminum theme provides a familiar Mac look and feel. Here's an example of the Aluminum theme in Word.
The Colorful theme brings the primary accent color of the app to the ribbon. Here's an example of the Colorful theme in Word.
Turn on Dark Mode on macOS
To use Dark Mode, you need to change the "Appearance" setting in the macOS System Settings:
Click the Apple menu at the top left.
Select System Settings > Appearance. (on older versions of macOS, choose System Preferences > General)
At the top of the dialog box you can switch the appearance of the operating system from Light to Dark:
Here's an example of Word in Dark Mode.
Turn off Dark Mode for a Microsoft app
If you'd like to have Dark Mode turned on for your operating system but want to turn it off for individual Microsoft 365 apps, follow these steps:
Go to the app preferences (For example, in Word, select Word > Preferences).
Select the General tab.
Under Personalize, select Turn off Dark Mode.
Note that this setting only affects the current app, so if you want it turned off in WordandExcel, for example, you'll need to repeat these steps in each of those apps.
Dark Mode in Outlook
To set Dark Mode in Outlook, first set it for macOS, as described above. Then do the following:
In Outlook, select Outlook > Preferences.
Select the General tab.
Choose the Appearance option you want:
Light Sets Outlook to light mode, regardless of what macOS is set to.
Dark Sets Outlook to dark mode, regardless of what macOS is set to.
System Matches your macOS mode setting, either light or dark.