I would have used something like
Trigger: any door opened
Action:
Chime
Set switch to red
Wait for condition all doors closed
Set switch to green
Then make a second rule
Trigger: any door close
Action:
Chime 2
While its not huge it is less impact on the hub
Also you may want to look into this all [RELEASE] Switch Dashboard - "Turn your LED status switches into mini-dashboards""