1. Launch Outlook 2011 for the Macintosh and log into your Exchange account.
2 Click on the Calendar button in the lower left corner of the Outlook window.
3. Double click the existing meeting you wish to assign a category. Go to Categorize and select the category and color you wish to use.
4. If none of the categories match what you wish to use click Add New and type in a name of your category and click OK.