Problem: Using OWA and Outlook 2010 on an Exchange 2010 server, we created two separate calendars (to go along with the users default cal) within one users account and then shared them out with â€œEditâ€ rights. All users who had access were able to create and delete appointments as planned but was unable to see the custom color categories that were created.
Solution: Turns out this was a rights issue. Not for the two extra calendars but rights to the main calendar. In order to see the custom categories, you need to make sure that the users have â€œReviewerâ€ rights to the main calendar. In our case, we set default to reviewer and then we were able to utilize the custom categories on the sub-calendars.