How to Change the Outlook Theme: A Complete Guide

Microsoft Outlook gives you meaningful control over how the application looks and feels — from the overall color scheme of the interface to the background patterns that appear in your email composition window. Understanding the difference between these layers of customization helps you make changes that actually stick and work across your setup.

What "Theme" Means in Outlook (It's Not Just One Thing)

Before diving into steps, it's worth clarifying that Outlook uses the word "theme" in two distinct ways:

• Office Theme — This controls the overall color scheme of the Outlook application itself (the ribbon, sidebar, and UI elements). Options typically include Colorful, Dark Gray, Black, and White.
• Document Theme — This applies to the fonts, colors, and formatting styles used inside individual emails you compose, similar to how themes work in Word or PowerPoint.

Mixing these up is the most common source of confusion. Changing one won't affect the other.

How to Change the Office Theme in Outlook

The Office Theme setting affects how the entire Outlook application looks — not just your emails.

In Outlook for Windows (Microsoft 365 / Outlook 2019–2021)

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 carries across all Office apps signed into the same Microsoft account — so switching to Dark Gray in Outlook will also switch Word and Excel to Dark Gray. 🎨

In Outlook on the Web (Outlook.com / Microsoft 365 Web)

1. Click the Settings gear icon in the top-right corner
2. Select View all Outlook settings
3. Navigate to General → Appearance
4. Choose your preferred color theme or accent color
5. Click Save

The web version offers a wider palette of accent colors compared to the desktop app, though the structural layout options remain more limited.

In the New Outlook for Windows (2024 and Later)

Microsoft has been rolling out a redesigned Outlook client. In the new version:

1. Click the Settings gear icon
2. Go to General → Appearance
3. Select a theme from the visual grid

The new Outlook aligns more closely with the web experience, offering color themes alongside a light/dark mode toggle.

How to Enable Dark Mode in Outlook

Dark mode is related to — but separate from — the Office Theme setting. Here's how each version handles it:

On Mac, Outlook respects the system-level dark/light mode set in System Settings → Appearance, rather than providing its own toggle in most versions.

How to Change the Email Composition Theme

This is the second type of theme — the one that affects fonts, colors, and formatting inside emails you write. 🖊️

Setting a Default Theme for All New Emails

1. In Outlook Desktop, go to File → Options
2. Click Mail in the left panel
3. Under the Compose messages section, click Stationery and Fonts
4. Click the Theme button
5. Browse the theme gallery, select one, and click OK

This sets a default look for all outgoing emails — including font choices and background colors. Keep in mind that recipients see these styles only if their email client supports HTML formatting. Plain-text readers will see none of it.

Applying a Theme to a Single Email

You can also apply a theme one email at a time without changing your default:

1. Open a new email composition window
2. Go to the Options tab in the ribbon
3. Click Themes
4. Select from the available theme gallery

Variables That Affect What You Can Actually Change

Not all versions of Outlook offer the same customization options. Several factors shape what's available to you:

• Subscription type — Microsoft 365 subscribers tend to get more frequent UI updates and may see options that Outlook 2019 standalone users don't
• Operating system — Mac users have fewer in-app controls because Outlook for Mac delegates appearance to macOS system settings
• Admin policies — In a corporate environment, IT administrators can lock or restrict theme settings through Group Policy, meaning some options may be greyed out regardless of what you try
• Outlook version — The classic desktop client, the new Outlook for Windows, and the web app have meaningfully different settings menus
• Account type — Personal Microsoft accounts and work/school (Azure AD) accounts sometimes see different feature sets in the web version

Why a Theme Change Might Not Appear to Work

A few common reasons theme changes don't seem to apply:

• Multiple accounts open: Office Theme syncs to the signed-in Microsoft account, but only if you're connected. Offline changes may not persist.
• Cached display settings: Closing and reopening Outlook fully (not just minimizing) often resolves display glitches after a theme change.
• IT-managed devices: Organizational policies may override personal theme preferences, particularly for the dark mode and Black theme options.
• Old Outlook build: Some theme options were introduced in specific update releases. If your Outlook hasn't been updated recently, options may be missing from your settings menu entirely.

The Version Question

The path to changing your Outlook theme looks noticeably different depending on whether you're using the classic desktop app, the new Outlook for Windows, the Mac version, the web app, or the mobile app. Each has its own settings structure, and the degree of customization available varies accordingly. 🖥️

Your specific version, operating system, and account configuration determine which of these paths actually applies — and which options you'll see when you get there.