How to Change the Outlook Color Theme: A Complete Guide

Microsoft Outlook gives you more visual control than most people realize. Whether you're staring at a bright white inbox for eight hours a day or just want your email client to feel less generic, changing the color theme is a straightforward process — once you know where to look. The challenge is that the steps vary depending on which version of Outlook you're using, and the options available to you depend on factors like your Microsoft 365 subscription and operating system.

What "Color Theme" Actually Means in Outlook

Outlook uses the term Office Theme (sometimes called Office Background or Color Mode) to describe the overall visual appearance of the application. This includes:

• Dark Mode / Light Mode — the most impactful visual change, switching between a dark or light interface
• Office Theme colors — accent colors applied to ribbons, buttons, and UI elements (such as Colorful, Dark Gray, Black, or White)
• Office Background — a subtle decorative pattern applied to the top ribbon area

These are separate settings, and changing one doesn't automatically change the others. Many users only discover one of these layers and miss the others entirely.

How to Change the Color Theme in Outlook for Windows (Microsoft 365 / Outlook 2019–2021)

The most common version most people are using falls into this category.

1. Open Outlook and click File in the top-left corner
2. Select Office Account (sometimes listed as just Account)
3. Under Office Theme, click the dropdown menu
4. Choose from available options: Colorful, Dark Gray, Black, or White

The change applies immediately and — importantly — it syncs across all your Microsoft Office applications. If you switch to Dark Gray in Outlook, Word and Excel will follow.

Enabling Dark Mode Specifically

Dark Mode in Outlook for Windows is handled slightly differently from the Office Theme selector:

1. Go to File → Options → General
2. Under Personalize your copy of Microsoft Office, find the Office Theme dropdown
3. Select Black for the darkest available option

Alternatively, Outlook will respect your Windows system dark mode setting if you've enabled it under Windows Settings → Personalization → Colors. Not all Outlook versions respond to this automatically, so manual adjustment through the Office settings is more reliable.

How to Change the Color Theme in Outlook on Mac

The Mac version of Outlook follows a slightly different path:

1. Open Outlook and click Outlook in the top menu bar
2. Select Preferences
3. Click General
4. Under Appearance, toggle between Light, Dark, or Match System Setting

The Match System Setting option is particularly useful for Mac users who switch between light and dark mode based on time of day using macOS's automatic appearance scheduling.

Outlook on the Web (Outlook.com and Microsoft 365 Web)

If you access Outlook through a browser, the theming options are found in a different location:

1. Click the Settings gear icon (top-right corner)
2. Select View all Outlook settings at the bottom of the panel
3. Go to General → Appearance
4. Choose your preferred theme from the visual options provided

🎨 The web version offers a broader range of decorative themes compared to the desktop app — including seasonal and illustrated options — though these are more cosmetic than the deeper dark/light mode changes.

Outlook Mobile (iOS and Android)

On mobile, Outlook respects your device's system appearance setting by default:

1. Tap your profile icon in the top-left
2. Go to Settings
3. Scroll to find Appearance or Theme
4. Toggle between Light, Dark, or System Default

Variables That Affect Your Options 🖥️

Not every version of Outlook offers the same theme settings. What's available to you depends on:

Common Issues When Changing Themes

Theme reverts after updates — Office updates occasionally reset theme preferences. Re-applying after a major update is normal.

Reading pane doesn't change — Email message backgrounds are controlled by the sender's email formatting, not your theme. A dark mode interface won't automatically invert white email backgrounds, though Outlook 365 has a "Dark Mode for email content" toggle that attempts this.

Theme applies to all Office apps — This surprises some users. The Office Theme setting is application-wide. If you want dark mode only in Outlook, that level of isolation isn't available through standard settings.

Black vs. Dark Gray — These look similar but behave differently. Black produces higher contrast and is preferred by users with light sensitivity, while Dark Gray is generally considered easier on the eyes for extended reading sessions.

The Part That Depends on You

The mechanics of changing Outlook's color theme are consistent — but which combination of settings actually works best is where individual setups diverge. Someone on a managed corporate Microsoft 365 account may find certain options grayed out entirely. A user switching between desktop and web Outlook daily will need to configure each separately, since preferences don't always sync between platforms. And anyone sensitive to contrast levels will find the difference between Dark Gray and Black meaningful in practice, while others won't notice it at all.

Your ideal configuration depends on how you use Outlook, where you use it, and what your eyes actually respond to across a workday.