The varchar field
OUTLOOKCATEGORY is synchronized with the category from the outlook/exchange meeting. Add the column to the agenda query and build custom to map a CSS class with the string value of the Outlook category.
When users add custom categories in Outlook or if multiple languages are used, since we only have the text value of the category, mapping it with colors is complex.
Note that also
EXTMODE is a synchronized field from exchange. It will contain the "Show as" value (Free, Tentative, Busy, Out of Office) from
This field is also interesting to map colors with