Change the color of unread messages

1. On the View tab in classic Outlook, select   View Settings in the Current View group.

2. Select Conditional Formatting.

3. In the dialog box, select Add to create a new blank rule, name your rule, then  choose Condition. 

4. In the Filter dialog, select the More Choices tab.

5. Select the checkbox for Only items that are and make sure it shows unread. Select OK.

6. Select Font, make a selection from the Color drop-down list, then select OK three times.

Tip: To learn more, see Automatically change incoming messages, colors, and fonts.