Hi @Eray Utku ,
In short, can I edit a label to make a separate visual marking in Outlook and a separate visual marking in other Office applications?
As far as I know, I am afraid this is currently not feasible.
Given this, I just tried submitting the idea via the dedicated feedback portal for MIP. I'll leave the thread link below so that you or other community members can vote or comment there as well. Let's hope this feature can be realized in the future.
https://feedbackportal.microsoft.com/feedback/idea/1664deb5-1b87-ed11-a81b-6045bdaf6a9e
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