We call them 'badges' and they mark a position, honor, support status, etc.
In my case, I was honored with 'Member of the Month' so got the Orange badge
I am a site supporter at both Level 5 and Level 4, which got me the 2 support badges.
I was recruited as a 'Member Relation Manager' which added the silver/black badge
and was later recruited as a Super Moderator which added the blue badge.
There are other badges available like Military or Emergency services that require qualification/verification to acquire.