That icon shows a player’s Endorsement level, while the colours represent how many endorsements of each kind that player has received:
- Sportsmanship in green
- Good Teammate in purple
- Shot Caller in orange
You can endorse other players at any time after a quick play or competitive match has ended but before ending the next match that allows endorsements.
Some arcade game modes also support endorsements, in both competitive and non-competitive versions:
- 3v3 Group Elimination
- Capture the Flag
- Lúcio Ball
- Team Deathmatch
For more information, visit the official website’s page on endorsements.
Source : Link , Question Author : Community , Answer Author : Wrigglenite