I'm hoping to use it to set a color code for the task in Outlook for my users but cannot find any documentaion on how to use it. What I find online (Specify a collection or dictionary variable for the list of the categories) isn't very helpful.
How to utilize the "Categories" section for the Exchange Online Create Task action
+6
+15You're not going to like my response because it isn't necessarily helpful - but more of a question - why would you want to set a category colour for someone else? For example, I use purple for appointments outside of work, orange for meetings that may be able to be moved, red for meetings I cant move, yellow for floating items... green for things I'm excited about. But I have a co-worker who uses her category tags for client names. Another uses it for prioritization.
So if you assign purple to all three of us... it's going to mean something different (and tagged thusly) if you do it automatically...
Playing devil's advocate here 
i'm curious about your reason!
Rhia
+6I understand your point of view. I have a situation where my group of engineers want a particular task directed to their to-do list so that task can be recalled IF someone else does a different function first. I was asked if I could put it in a common category that they would all mark as being top of their to-do list.
+6No I have not Tomasz. I ended up implementing with out a category called out. I would like to update one day if I find a solution however.
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