How to share color categories for Outlook 2010

Since there aren't many written sources for sharing categories, I thought it might be useful to discuss a bit on this topic and how can this be achieved in Outlook 2010.


As a background information for versions prior to Outlook 2007 category information was stored in the local registry. There is a binary key, called MasterList, located under HKCU\Software\Microsoft\Office\x.0\Outlook\Categories that contains the information on the categories.

The key will be written only if you customize the Master List.



Since Outlook 2007 the information on categories is stored on the mailbox (more specifically in a Mapi property on the item IPM.Configuration.CategoryList within the Calendar, called PR_ROAMING_XMLSTREAM).


When you will upgrade users to Outlook 2007/2010 from Outlook 2003, each user's categories and flags are still available. Flags, reminders, and labels will be rolled into categories for Outlook 2007/2010. Outlook will migrate category and flag information into the new categories structure.

Quick flags: When a user starts Outlook 2007/2010 for the first time, all existing quick flags migrate to categories. The same color is used, but date information is not retained. If an item has a reminder flag, the reminder is migrated separately.

Calendar labels: Labels also migrate when Outlook starts and are added to the user's categories list.

Other categories: Categories for non-mail items (such as tasks) migrate to Outlook 2007/2010 categories and a random color will be assigned to each category


Color categoryselections are stored in the users default mailbox storage location, which should be the mailbox on the server. This means categories now roam with the user. However, you may need to right click on the root folder, choose Properties and click the button to Upgrade to color categories. This will assign random colors to the categories.

Outlook 2007/2010 will no longer use the registry for a master category list. Instead, they are stored in the default message store (mailbox or pst). For example, if you are setting up a new system and using your old pst, the color categories will be available on the new system.


Although categories are not meant to be shared you might encounter scenarios in which an administrator for a shared mailbox would like to have the color categories visible for all the other users that access the shared mailbox.

The expected behavior is to only see the categories but not the colors.

However, if you want to make also the colors visible for other users there are two methods to achieve this: 

1. Add the shared mailbox as an additional mailbox and provide Reviewer permissions on the Calendar.

This is required as the Category list is stored on the Calendar.


This is how you are seeing the categories for the additional mailbox


2. Add the shared mailbox as an additional Exchange Account.

In this way you will have two category lists, one for each Exchange Account.

For this you need know the credentials of the shared mailbox (unless you have Full Mailbox Access) and have at least Reviewer Permissions on the Calendar, like in method 1.


Note: Adding the additional Exchange Account with delegate access is considered unsupported.



This is how you are seeing the categories for the additional Exchange Account


This is how you are seeing the categories for your own account



For all the methods above, the already categorized items from the shared mailbox will have the color category visible.


To summarize this, there are several options for sharing and managing color categories in Outlook 2010:

1. Adding the shared mailbox as an additional mailbox and provide Reviewer permissions on the Calendar.

2. Adding the shared mailbox as an additional Exchange Account

Each of them have their own advantages and disadvantages, so please review the options and adapt them to your own environment, accordingly.


Please feel free to comment, raise questions or add extra information on the topic.


Comments (28)

  1. Catalic says:

    You culd try to assigt everyone editor/owner permissions.

    As far as i know every person with this kind of permission should be able to see the categories for that mailbox. Else you will see you own category when opening the shared calendar.

  2. FlorinaB says:


    @Scott: Categories on public folders are only visible if they are on the default list a.k.a. "Master Category List". You can force this by GPO. In the Administrative templates for your Office version you can find a policy called "Add new categories" under Miscellaneous. You can add there a list of custom categories that will be deployed to everyone in the Organizational Unit. They will append to the user's list of categories and will not overwrite any of their custom ones.

    This can allow users to set one of those categories on items from the public folder and other users having access to it, to see them.

    @Bruno: In order to make changes to the categories list you need to have Editor permissions or you can ask the owner of the calendar to change them accordingly.


  3. FlorinaB says:

    Hi Michelle,

    The article describes step by step what you need to implement in order to have this option working.

    If you are using Outlook 2010 I would recommend checking the permissions from your manager's machine on the Calendar folder. They need to be at least Reviewer, if you have his mailbox added as an Additional Mailbox.

    Otherwise you can use the Additional Exchange Account option.

    Please see the blog for the technical details on how to configure either of these two options.

    Hope this answers your question.



  4. FlorinaB says:

    Hi Tanya,

    If you have two calendar folders under the same account you cannot divide categories. They will be shared.

    However you can configure a separate account for your team, give yourself permissions at least on the Calendar and open it from your Outlook profile. This way you will be able to have two different lists of categories, specific to each calendar.


  5. Catalic says:

    Hi Mike,

    If you assign owner permissions on the shared mailboxresource mailbox calendar you should be able to customize it's categories.

    You should also be able to view and use its permissions if you have a lover permissions set, like reviewer.

    So you need a master user which sets the categories and the rest of the users working with the shared calendar categories should be able to use them as long as they have folder permissions.

    I am not quite sure what is the minimum requirement to actually use them but that you could test.

    There is no need for any other permissions on the mailbox.

    Hope this helps

  6. FlorinaB says:


    you can use a GPO to deploy a standard set of categories for a certain group of users. I can get back to you tomorrow with more details.


    Please make sure the permissions on the shared calendar are set correctly. Otherwise you can also try in online mode to see if you are prompted with a specific error message.

  7. Moiz says:

    Very Useful stuff, Thanks

  8. tanya1 says:

    I'm using Outlook 2010 and have 2 calendars under the same account (one for me and one for my team). I do not want the two calendars to share category colors. How do I separate them?

  9. Michelle says:

    I am a surrogate on my boss's calendar and I need to be able to set/change categories on her calendar.  Why can't I do this from my machine?  How do I resolve?  Please advise.  Thanks.

  10. Scott says:

    How can I set the category colors for a public folder calendar? I would like everyone that has access to the calendar to all see the sames colors.

  11. Bruno says:

    I have my calendar and a shared calendar that I work off of.  The shared calendar, which I do not have admin rights to, recent had the colors changed.  I am trying to get them changed back.  Does anyone have any input for me?

  12. Marko says:


    I was hoping you might help me. I would like to backup my colour categories (I am using Outlook 2007) to be able to transfer them to Outlook 2007 on another computer together with all the e-mail messages (that I would transfer via the Outlook.pst file). How can I do that? Are the colour categories perhaps stored in the same Outlook.pst file so they would be automatically transferred together with the e-mail messages?

    Thank you in advance,


  13. mike says:

    Is there a way to do this without adding mailbox?  We don't want other users to see mail, just the calendar.   If I just shared the calendar no colors show up.   Adding the whole mailbox is not an option as it would allow user to see private mail and contacts.

  14. Greg Lambert says:


    is there a way to export categories from outlook 2010 to other users? in our company we have an calender with different categories. i added the categories so only i see them. is there a way to export them and add them on every other client that needs it? Thanks a lot!

  15. Don says:

    Similar Q as Greg.

    We have a shared calendar which tracks all events for our field staff (who are sometimes in the office and who frequently schedule events for each other based upon who is in the office handling calls).

    We want to be able to look at that shared calendar and tell by colour category who's event it is.

    Ideally, we'd also like to be able to change the category name from the default color to the associated staff's name (we can leave the categories with their default names if needed).

    That is, instead of 'deep red' we want that categoty to be 'Don'; instead of 'green' we want that catgory to be 'Mary; … and of course have everyone be able to see the assigned colours (regardless of who added the event to the calendar).

    We can get th events to show and have the events state the category but no colours.

  16. Greg Lambert says:

    Only free Solution is to add the same categories to each client which will use it. We did it the same and it works.

  17. Bruno says:

    All our office staff have calendars shared with everyone else, how to i copy categories to a newly created calendar in Outlook 2010?

  18. tom says:

    I'm having a little difficulty with the categorising of mails in 2007. One of our managers is trying to categorise another user's mailbox, after 10 or so seconds this reverts back to uncategorised – anyone know why?

  19. debi says:

    Our business utilizes the Outlook email account through Google mail.  There are 4 people who have access to the main executive's calendar. We are trying to colorize the main calendar to discern meetings, etc.  I have been able to change the category colors before at another company but it was on the standard Outlook system.  Could Google mail be blocking our allowance to colorize the calendar to show up on the Executive's calendar?  If so, how can we get around this? Please respond to

  20. Chris says:

    I am using outlook 2007, I've shared my calendar however they are not seeing the colors. How do i share the colors to the user's. The calendar is originates from a different user box, but i have full permission. is there a way for me to pull the collor
    category in from the originator?

  21. Heather says:

    We are using Outlook 2010. My company uses many shared calendars but they are setup by corporate. Those calendars have "calendar tools tab" which has colored categories set up for each calendar. Now I have the joy of making a calendar for our office to
    share. In this calendar I need the option of categorizing names. So they can color code the things they put in the calendar. However, I cannot get the Caledar tools to show for the new calendar that I created. Instead if someone adds an event to the calendar
    only thier personal categories show up. Does anyone know how to add the calendar tools to a shared calendar with categories that are assinged for the that calendar only. I have tried everything. I can create a tab on the calendar, but can not put anything
    in it. Thanks for your help.

  22. Ciaran says:

    Is it possible to have multiple category columns side by side?

  23. Gilles says:

    Instead of creating a calendar in a separate mailbox that must be added to all involved users, can we do the same with a calendar created in the Public Folders and share the colour categories it uses ?
    Many thanks for your help.

  24. Hello,
    I know I can create a rule to auto-color an appointment in a calendar based on some criteria but i like to auto-color an appointment to a shared calendar that everyone can see. I tried creating a rule but it applies to one user instead of globally.

    Thanks for your help


  25. Guada says:

    Hi! I have a similar question: I need to create multiple categories, that my team-mates will also have to duplicate. Is there a way to just share the categories I create for them to use, without sharing my calendar? Thanks!

  26. mavazi says:

    Hi, is it possible to see who of my team categorised a email in a shared email folder?
    Many Thanks,

  27. Trish says:

    I need to be able to move a Master Category List from Outlook 2003 to Outlook 2013. How do I transfer that without a third party program? Thanks.

  28. Kevin says:

    Am I to understand that if I create a separate mailbox and exchange account for this calendar, the "Calendar Owner" can then populate a calendar with events and then share it with a group of people on the Exchange Server? If so (and this is my main question),
    would it retain the colors and categorize assigned by that Calendar Owner's account (in that, all users would see the same categories and colors)?

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