Here is the authoritative guide to the lights:
The power light is by the power/CT ports and should be solidly lit in red or green whenever the Sense monitor is powered on.
The “status” light is by the antenna port and can be lit up in red, green, or yellow. Red is indicative of a problem, green (or no light) means everything is good, and yellow usually means some sort of Wi-Fi error.
Of course, most people shouldn’t be taking their panel covers off to check these lights, so they’re not meant to be super valuable to the end user. They’re more for diagnostic purposes on our end.