I am trying to change the icon for EPIC and APM issue types because it has the same purple color and it is somehow confusing. I have 2 questions:
1. How can I change the icon without impacting the icons of the other projects.
2. After changing the icon, will Jira send an email notification to all users that an icon has been changed? I want to avoid sending email notification to the users. In the past, I did some changes in a particular field, an email was sent to some 10000 recipient causing "Medium-severity alert: Email sending limit exceeded".
No. Administrative changes to the way things are displayed are not issue changes. So there's nothing to write to the issue, the issue history or to notify people about. (The exception is workflow changes - they do amend issues, so you do get notified)
You can change the icon of an issue type going to Administration-> issue types -> Click on ... for the issue type -> Modify-> Select picture.