What you can change color in Outlook, and where to find it
Outlook lets you change colors in three main places: your email categories (the labels you assign to messages), your calendar events, and the background of your message reading pane. You cannot change the color of the entire Outlook interface itself — the ribbon, sidebar, and folder list stay the same. But you can make individual emails, calendar items, and category tags stand out in whatever color you want.
The steps differ depending on what you are coloring and which version of Outlook you use. Outlook for Windows, Outlook for Mac, and Outlook on the web (the browser version) all have slightly different menus. This guide covers the most common: Outlook for Windows on a desktop or laptop.
Key Takeaways
- Categories are the fastest way to color-code your emails — assign a category to a message, and it gets a colored label and a colored flag in your inbox.
- Calendar events have their own color picker separate from categories, found in the event details window.
- You can customize the color of each category to match your workflow, such as red for urgent or blue for a specific project.
- On a Mac or in Outlook on the web, the steps are similar but the menu locations are different — look for "Categorize" or "Categories" in the main toolbar.
How to color-code emails with categories
Categories are the main tool for coloring emails in Outlook. When you assign a category to a message, it gets a colored tag next to the subject line in your inbox and a colored flag in the message itself. To assign a category, right-click on an email in your inbox and select Categorize. A menu appears with preset categories: Red Category, Orange Category, Yellow Category, and so on. Click the one you want.
The email now shows that color tag. You can assign the same category to multiple emails at once by selecting them (hold Ctrl and click each one), then right-clicking and choosing Categorize. This is useful for grouping emails by project, sender, or urgency without moving them to different folders.
If you want to rename a category or change its color, right-click on any email with that category assigned, select Categorize, then click All Categories at the bottom of the menu. A window opens showing all your categories. Select the one you want to edit and click Rename or Color. You can change "Red Category" to "Urgent" or swap its color from red to orange. The change applies to every email that already has that category.
How to change the color of calendar events
Calendar events have their own color system separate from categories. To change the color of a single event, double-click it to open the event details. Look for a Categorize button in the ribbon (the toolbar at the top), or look for a color option in the event window itself. In newer versions of Outlook, there is a small colored circle or square you can click to pick a new color.
If you do not see a color picker in the event details, try right-clicking the event directly on your calendar and selecting Categorize, then choose a color. Some versions of Outlook also let you click and drag an event to a different calendar (if you have multiple calendars), and each calendar can have its own default color.
Unlike email categories, calendar event colors do not always sync across devices. If you use Outlook on your phone and your desktop, a color you set on your computer may not appear the same way on your phone. The event itself syncs, but the color display can vary.
Changing colors in Outlook on the web
If you use Outlook in a web browser instead of the desktop app, the steps are similar but the menus are in different places. Open an email and look for a Categorize button in the toolbar above the message. Click it and select a color from the list. You can also right-click an email in your inbox and choose Categorize.
To rename or customize categories in the web version, click the gear icon in the top right corner, then select View all Outlook settings. Go to Mail > Categories. Here you can create new categories, rename existing ones, and assign colors to each. Changes you make in the web version sync to your desktop Outlook app.
Changing colors on Outlook for Mac
On a Mac, open an email and look for the Categorize button in the toolbar. Click it and select a color. If you do not see the button, go to the Home tab in the ribbon and look for Categorize there. You can also right-click an email and choose Categorize from the context menu.
To edit categories on a Mac, go to Outlook > Preferences in the menu bar, then select Categories. You can rename categories and change their colors here. The process is the same as on Windows, but the menu path is different because Mac uses the Preferences window instead of Settings.
Why colors disappear or do not sync
If you color an email on your desktop but the color does not show up on your phone, or if a category color suddenly changes, it is usually because of how Outlook syncs across devices. Desktop Outlook and Outlook on the web use the same color system, so changes sync between them. But Outlook mobile apps (on iPhone or Android) have their own color system and may not display desktop colors the same way.
If a category color reverts to default after you change it, check whether you are using a shared mailbox or a delegated account. Shared mailboxes sometimes reset category colors when multiple people edit them. If you are the only one using the account, try closing and reopening Outlook to force a refresh.
Using colors to organize your workflow
The most useful approach is to pick a consistent color scheme and stick with it. For example, you might use red for emails that need a response today, yellow for emails to read later, and blue for emails from a specific project. Create these categories once, name them clearly, and then you can quickly assign them to incoming emails without thinking.
You can also combine categories with rules. A rule is an automatic action Outlook takes when an email arrives. For instance, you can create a rule that automatically assigns the "Project X" category (and its color) to every email from a specific sender. Go to File > Manage Rules & Alerts to set this up. This saves you from manually categorizing emails you know will always belong to the same group.
Frequently Asked Questions
Can I use colors without assigning categories?
Not in the traditional sense. Colors in Outlook are tied to categories — you cannot color an email without assigning it a category. However, you can create a category with a blank name and just use the color, so it looks like a pure color label with no text.
What if I delete a category — do the emails lose their color?
When you delete a category, emails that had that category assigned will no longer show the color tag, but the emails themselves are not deleted. You can reassign them to a different category to color them again. Outlook warns you before deleting a category if emails are using it.
Can I assign multiple colors to one email?
Yes. You can assign multiple categories to a single email, and each category shows its own colored tag. Right-click the email, select Categorize, and click more than one color. The email will display all the colored tags you assigned.
Why does my category color look different on my phone?
Outlook mobile apps use a different color palette than desktop Outlook. A color you set on your computer may appear slightly different on your phone because the apps render colors differently. The category name and assignment stay the same — only the visual appearance changes.
Can I change the color of the Outlook background or theme?
You can change Outlook's overall theme (dark mode, light mode, or colored themes) by going to File > Options > General and looking for Office Theme. But you cannot change individual colors of the ribbon, sidebar, or folder list. Only email categories and calendar events have customizable colors.