Outlook: Color Labels Don't Persist in Meeting Requests

When I send a meeting request to someone else in my Exchange Server organization, the invitee who accepts the appointment doesn't see the color label on the copy of the appointment in his or her Calendar folder. Is there a way to make the color labels persist?

I haven't been able to find a way to make color labels persist on meeting requests. The field that holds the color label information is definitely present on the meeting request that the invitee receives, but it's always set to the value for no color.