Colour-code your Outlook calendar with categories
Categories let you colour individual Outlook items by project, client or type, independently of which calendar they’re on. They are your labels, not the organiser’s. Arte Soft, the developer of Cloud Calendars, explains.
Categories vs calendar colour
| Category | Calendar colour | |
|---|---|---|
| Applies to | Individual items (several per item) | A whole calendar |
| Seen by attendees | A category you apply to a received meeting does not change the sender’s Outlook view | Not applicable |
| Also used for | Mail, contacts, tasks | — |
What most people assume
If I colour a meeting red, everyone in the meeting sees it red.
Assign a category
New Outlook and Outlook on the web: right-click the event and choose Categorize, or open it and choose Categorize on the Event tab, then pick a category. Repeat to add more than one. Use Manage categories or All Categories for more options.
Classic Outlook: right-click the item and point to Categorize, or use Categorize in the Tags group of an open item. All Categories lets you create new ones.
Categories are personal
Microsoft says a category applied to a meeting you received does not affect the other person’s Outlook view; the selection applies to the item in your own calendar. The same category list can be used for other Outlook item types such as mail, contacts and tasks. This is a personal organization tool, not a sharing or access-control setting.
Categories also differ from calendar colours, which colour a whole calendar. Use calendar colours to tell accounts apart and categories to tag individual items.
Worked example: a consultant with three clients
A fictional consultant creates three categories, Client A (blue), Client B (green) and Admin (grey), and applies them to meetings in their work calendar. A meeting with both clients gets two categories.
When Client A’s project manager sends an invitation, the consultant tags it blue on their own calendar; the project manager’s calendar is unaffected.
Check: in week view, inspect the items tagged for each client before agreeing more work. For a meeting with two categories, count its duration only once if calculating total occupied time; do not assume an item’s displayed color represents every assigned category.
What it looks like
Cloud Calendars overview, using our product images. Provider settings and protocol examples described in this guide are separate from the screens shown here.
What to do
- Create a small set of categories for your main projects or types.
- Apply them with Categorize; add more than one where needed.
- Use calendar colours to separate accounts, categories to tag items.
- Don’t rely on categories to signal anything to attendees.
Questions
- Will attendees see my categories?
- Microsoft says a category you apply to a received meeting does not affect the other person’s Outlook view. Use explicit communication, not a personal category, to signal something to attendees.
- Can one meeting have two categories?
- Yes. Microsoft says you can assign more than one.

