How do I turn on dark mode in new Outlook?

Select Settings, then General, then Appearance. Under Dark mode choose Dark and select Save. To turn it off, choose Light or Use system settings in the same place. If emails look wrong afterwards, use Turn on the lights at the top of the reading pane to see the original formatting.

Why is the email background still white in Outlook dark mode?

Dark mode recolors most messages, but a sender's own formatting can still leave a light background. In new Outlook, select Turn on the lights at the top of the reading pane for the original look, or use Light Reading Pane on the View tab. In classic Outlook, check the option to never change the message background color.

Does my dark mode change how recipients see my emails?

Microsoft describes the compose buttons Toggle light background and Toggle dark background as settings for your own message window. Recipients see the message in their own app, with their own theme. Because you can't know which they use, check that your logo and signature stay readable on both light and dark backgrounds.

Outlook Dark Mode: How to Turn It On and Fix White Emails

By Mirko Peters · 2026-11-12

Outlook dark mode explained: how to turn it on in new Outlook, classic Outlook, the web, Mac and mobile, and how to fix a white message background in dark mode.

To turn on dark mode in Outlook, open Settings, go to General, then Appearance, and set Dark mode to Dark. That's the path in new Outlook for Windows, and Outlook on the web uses almost the same menu. Classic Outlook for Windows gets dark mode from the Black Office theme, and the mobile apps have their own switch. This article is for Outlook users who want a darker inbox for evening work, and it also covers the part most people really search for: why some emails still show up bright white, and what to do about it.

Key points

In new Outlook, go to Settings, General, Appearance, set Dark mode to Dark and select Save.
In classic Outlook for Windows, dark mode comes from the Black Office theme under File, Options, General.
To read a white-background email in dark mode, select Turn on the lights at the top of the reading pane, or use Light Reading Pane on the View tab.
Outlook for iOS follows the system setting by default, and Outlook for Android offers a Dark Theme switch under Preferences in Settings.
Dark mode changes how you see messages. Design emails so logos and signatures stay readable on both light and dark backgrounds.

What Outlook dark mode actually changes

Dark mode swaps the light interface for a dark one, and Microsoft says Outlook can also recolor the messages you read to match. In new Outlook, dark mode gives the reading pane a dark background. In classic Outlook, Microsoft's page on the look and feel of Microsoft 365 says that in the Black theme, Word and Outlook recolor documents and emails by default to match the app.

That is where the confusion starts. A lot of email arrives as HTML with its own colors, logos on white backgrounds and fixed formatting. Outlook tries to recolor it, but the result is not always pretty, and it can differ message by message. So you have two jobs: switch dark mode on, and know how to bring back the original look when a message needs it.

Which Outlook are you using? If you see a File menu in the top left, you're on classic Outlook. If you see a Settings gear and no File menu, you're on new Outlook or the web.

How to turn on dark mode in new Outlook for Windows

Microsoft's page on dark mode in Outlook gives these steps for new Outlook.

Select Settings, then General, then Appearance.
Under Dark mode, select Dark.
Select Save.

To turn it off, go to the same place and choose Light or Use system settings. The second option makes Outlook follow your Windows setting, so the app goes dark in the evening if Windows does.

Classic Outlook for Windows

Classic Outlook doesn't have a toggle called dark mode. Microsoft describes it as part of the Office theme: the Black theme is the dark mode choice. Per Microsoft's page, the steps are:

Open a Microsoft 365 app. For Outlook, select File, then Options, then General.
Open the Office Theme drop-down and choose a theme.

The themes are:

White: bright and clean.
Dark Gray: softer grays with higher-contrast controls.
Black: the darkest option, and the one Microsoft identifies as dark mode.
Colorful: like White, but the top of the ribbon uses the app's color.
Use system setting: the default. It switches between White and Black based on your Windows light or dark mode, which you set in Settings, Personalization, Colors, Choose your mode.

The Office theme applies to all Microsoft 365 apps, so changing it in Outlook also changes Word and Excel. That's usually what people want, but it's good to know before you wonder why your spreadsheets went dark.

Outlook on the web

Outlook on the web has its own setting. Microsoft's page on changing the look of your mailbox says to select the Settings gear, go to General, then Appearance, and choose a theme or a mode to turn on dark mode. The page doesn't list the names of the modes, so check the Appearance screen on your own mailbox.

Outlook for Mac

Microsoft's pages I opened don't give Mac steps for dark mode. A community answer on Microsoft's Q&A site describes this path: open Outlook, open the settings (older versions call them Preferences), select General, and in the Appearance section click Dark. It also says to choose System if your Mac switches between light and dark on a schedule, so Outlook follows it. Since that answer comes from a volunteer, not from Microsoft's documentation, the menu names may differ slightly in your version.

Outlook for iOS and Android

On iPhone and iPad, Microsoft's article says to open Outlook's Settings, tap Appearance and choose Light, Dark or System Default. By default, Outlook for iOS version 4.5.0 or later follows the system Dark Mode setting. Choose System Default to keep it that way. Choosing Light or Dark overrides the system setting. On iOS 12 or earlier, the setting is a Dark Appearance toggle under Preferences.

On Android, Microsoft's Android article says to open Outlook's Settings and find the Dark Theme switch under Preferences. You get two options: Dark Theme, which keeps dark mode on until you turn it off, and Set by Battery Saver, which turns it on whenever the device is in Battery Saver mode.

Fixing the white message background

This is the most common complaint, and Microsoft gives several fixes for new Outlook.

Reading pane: select Turn on the lights at the top of the reading pane. That shows the message in its original formatting on a light background. If you don't see the button, select More. The same button brings back the original formatting.
Keep the pane light: go to the View tab and select Light Reading Pane. The interface stays dark while the reading pane and compose window stay light.
Compose window: on the Message toolbar, Toggle light background turns dark mode off for that window, and Toggle dark background makes the message window black.

In classic Outlook, the Black theme recolors emails by default. To stop it, Microsoft says to go to File, Options, General, open Personalize your copy of Microsoft Office and check the option to never change the message background color. Microsoft's page notes that the black color theme gives the message window a black background and that you can switch the message window to white if you prefer.

On Windows 11, a background effect called Mica may add a tint to the window. To turn it off, go to Windows Settings, Personalization, Colors, Transparency effects.

Which one should you pick? If you read mostly plain internal mail, leave recoloring on. If your inbox is full of newsletters and invoices with logos, use Turn on the lights per message or keep the reading pane light. Don't switch dark mode off completely because of a few bad senders.

How your emails look to other people

Dark mode is a setting on your device. The compose buttons Microsoft describes are for your own window: Toggle light background and Toggle dark background change how you see the message while writing. Nothing in Microsoft's pages says these toggles change what recipients receive. Recipients read your message in their own app with their own theme, so you can't control which one they use.

What you can do is write messages that survive both. These are my suggestions, not Microsoft rules.

Use a logo with a transparent background, or one that has a visible edge on both light and dark backgrounds. A black logo on a transparent background disappears on a dark screen.
Skip background images and forced colors in email bodies.
Keep your signature simple. Text signatures are the safest, and a signature image with a white box looks strange on a dark pane.
Send a test to yourself and read it once in each mode.
Add alt text to images so the meaning survives if the image is hard to see.

The article on how to change your signature in Outlook covers the signature editor in more detail.

Common mistakes

Looking for a "dark mode" switch in classic Outlook. It's the Office theme, under File, Options, General.
Forgetting the system setting. If you chose Use system setting, Outlook goes dark when Windows does. Change Windows or choose Dark or Light yourself.
Switching dark mode off because of one bright email. Use Turn on the lights or Light Reading Pane instead.
Assuming the Mac or web menu matches Windows. The names are close but not identical.
Designing emails only for white. A black logo on a transparent background is invisible in dark mode.
Ignoring the Android Battery Saver option. If your phone goes dark randomly, check whether Set by Battery Saver is selected.

Next step

Turn on dark mode in the version of Outlook you use, open your newest newsletter or invoice email and try Turn on the lights or Light Reading Pane. That takes a minute and tells you whether Outlook dark mode suits your inbox, or whether you'd rather keep the reading pane light.