Event color should be a personal setting, not affecting other people invited to the same event

Steps to reproduce

1. Have a Nextcloud with two users, a system wide smtp server should be configured and both users should have a valid email address in their profile
2. user1 invites user2 to an appointment
3. user2 accepts it
4. user1 edits the event and change the color of the event

Expected behavior

Color only changes for user1 (the organizer) but not for the invited people.
Also color changes should never trigger a event update mail.

Actual behavior

Color also change for the invited people and the they receive a notification about a updated invitation

Additional observation:

• if now the invited person change the color of the event, the calendar entry of the event owner is not affected (this is how it should be)
• If the event owner edits again his calendar and changes the color of the event, the color for the recipients gets updated again and the custom color they set in the previous step gets overwritten. They also receive again a mail notification that the invitation was changed.

Calendar app version

No response

CalDAV-clients used

No response

Browser

No response

Client operating system

No response

Server operating system

No response

Web server

None

Database engine version

None

PHP engine version

None

Nextcloud version

No response

Updated from an older installed version or fresh install

None

List of activated apps

Nextcloud configuration

Web server error log

Log file

Browser log

Additional info

No response

Start by reproducing the four steps with two users and verify whether changing the organizer's color alters the invitees' entries or sends update mail. Trace the event-color change and invitation notification behavior, then confirm that each user's color remains personal and that color-only changes do not trigger invitation updates.