Outlook highlights all unread messages in your Inbox using bold type. If you’d like something more flashy or subtle, simply change the formatting option. To do this, click your Inbox and choose View, Arrange By, Current View, Customize Current View. Click Automatic Formatting, click Unread Messages and click Font and set the color, font and size to use for unread messages. When you’re done, click OK – simple, and from now on, very colorful!