Three colours.
No more tab-hunting.
Stop flicking between sessions to see which one is waiting. Look up, and you know.
It needs you.
A permission prompt, a question, a plan waiting for approval. The widget's border turns red too, so you can't miss it.
It's working.
Reading code, running builds, writing changes. Leave it be and get on with something else.
Your turn.
It's finished and waiting for your next prompt. Double-click the light to jump straight into that session.