Internet Light
This flashes during set up, and then stays green for 2 minutes when you're done. It isn't on during normal use, but turns red if there is a problem. This light flashes green when the Hub's downloading a software update.
WiFi Light
This flashes during set up, and then stays green for 2 minutes when you're done. It isn't on during normal use, but turns red if there is a problem. This light flashes green if you press the WPS button.
Home Phone Light
This flashes during set up, and then stays green for 2 minutes when you're done. It isn't on during normal use, but turns red if there is a problem.
WPS Light
Pressing this button lets you use WiFi Protected Setup (WPS) to add a wireless device or computer to your network.
Base Light
This flashes during set up and will stay white during normal operation, but turns red if there's a problem.