New Outlook Category Colors in Mail: How It Works for Classic Outlook Users

If you use Classic Outlook and have opened the new Outlook for Windows, you may notice that category colors look different. The new Outlook uses a simplified color palette that does not match the 25-color system in Classic Outlook. This article explains how category color mapping works between the two versions and what happens to your existing categories when you switch.

Microsoft redesigned categories in the new Outlook to reduce the palette to 11 colors. Classic Outlook categories with non-mapped colors are automatically assigned to the nearest matching color in the new Outlook. This guide covers the color mapping rules, how to verify your categories in both versions, and the limitations you should know before switching.

Why Category Colors Change When Switching to the New Outlook

The new Outlook for Windows uses a redesigned category system with a fixed set of 11 colors. Classic Outlook provides 25 named colors plus an automatic color option. When you switch to the new Outlook, your existing categories and their names are preserved, but the color assignment may change.

Microsoft maps Classic Outlook colors to the new palette using a nearest-color algorithm. For example, Classic Outlook colors like Dark Blue, Teal, and Purple map to Blue in the new Outlook. Colors that do not have a direct match in the new palette are assigned to one of the 11 available colors. This mapping is one-way: changes made to category colors in the new Outlook do not appear in Classic Outlook with the same color.

Classic Outlook 25-Color Palette

Classic Outlook offers these named colors: Red, Dark Red, Orange, Dark Orange, Peach, Yellow, Green, Dark Green, Teal, Aqua, Blue, Dark Blue, Purple, Dark Purple, Lavender, Pink, Dark Pink, Maroon, Brown, Dark Brown, Gray, Dark Gray, Light Gray, Black, and White. Each color has a fixed RGB value.

New Outlook 11-Color Palette

The new Outlook uses these colors: Red, Orange, Yellow, Green, Teal, Blue, Purple, Pink, Brown, Gray, and Light Gray. The remaining 14 Classic colors are mapped to the closest match in this set.

Steps to Verify Category Colors Before Switching

1. Open the All Categories dialog in Classic Outlook
   In Classic Outlook, go to the Home tab. Click Categorize in the Tags group. Select All Categories from the dropdown menu. A dialog box opens showing every category you created and its assigned color.
2. Identify colors that will change
   Compare your category colors against the 11-color new Outlook palette. Any color not in the set of Red, Orange, Yellow, Green, Teal, Blue, Purple, Pink, Brown, Gray, or Light Gray will be remapped. Write down which categories use Dark Blue, Dark Red, Dark Green, Dark Purple, Dark Pink, Dark Orange, Peach, Aqua, Lavender, Maroon, Dark Brown, Dark Gray, Light Gray, Black, or White.
3. Switch to the new Outlook
   In Classic Outlook, toggle the Try the new Outlook switch at the top of the window. Wait for the new Outlook to load your profile and categories. This process takes a few seconds.
4. Open Categories settings in the new Outlook
   In the new Outlook, click Settings (gear icon) in the top-right corner. Select General and then Categories. The list shows all your categories with their new color assignments.
5. Manually adjust any mismatched colors
   If a category was mapped to a color you do not want, click the color swatch next to the category name. Choose a different color from the 11 available options. The change applies immediately to all items with that category.

Common Issues and Limitations When Category Colors Change

Categories appear with a different color after switching back to Classic Outlook

If you change a category color in the new Outlook and then switch back to Classic Outlook, the new color is not preserved. Classic Outlook reverts to the original color assigned before the switch. To keep the color consistent, change the category color in Classic Outlook before switching. Use the same color name from the Classic palette that maps to your desired new Outlook color.

Category color is missing or shows as gray in the new Outlook

Categories created in Classic Outlook with the Automatic color option are mapped to Gray in the new Outlook. To fix this, edit the category in Classic Outlook and assign a specific color before switching. Alternatively, after switching, select a different color in the new Outlook Categories settings.

New categories created in the new Outlook do not appear in Classic Outlook

Categories created in the new Outlook are stored in the cloud and sync to Classic Outlook only if you use the same Microsoft 365 account. Categories created in the new Outlook using a local account or a non-Microsoft 365 email account do not sync. To see these categories in Classic Outlook, create them in Classic Outlook instead.

Cannot assign a custom color to a category in the new Outlook

The new Outlook does not support custom color assignment. You are limited to the 11 predefined colors. If you need a specific color, use Classic Outlook to assign one of the 25 named colors that maps to your desired new Outlook color.

Item	Classic Outlook	New Outlook
Number of colors	25 named colors plus Automatic	11 fixed colors
Custom color support	No custom RGB input; only named colors	No custom RGB input; only predefined colors
Color mapping behavior	No mapping; color stays as assigned	Maps unmapped Classic colors to nearest match
Sync between versions	Category names sync; colors do not sync back	Category names sync; colors do not sync back
Where to change colors	Home > Categorize > All Categories	Settings > General > Categories

You can now manage category colors across both Outlook versions. Before switching to the new Outlook, review your category colors in Classic Outlook and note which ones will change. After switching, adjust any mismatched colors in the new Outlook Categories settings. For advanced color control, stick with Classic Outlook and use the 25-color palette.