DIAGNOSIS A solid amber light on the router means it's powered on but can't establish an internet connection from your modem. The power outage likely caused a timing issue where the Orbi booted up before your modem was fully ready, confusing the connection.
FIX You need to power cycle everything in the correct order. 1) Unplug the power from both your modem and the Orbi router. 2) Wait 60 seconds. 3) Plug only your modem back in and wait for all its lights to settle into their normal state (this can take 2-3 minutes). 4) Now, plug the Orbi router back in. Wait for it to boot. The ring light should pulse white, then turn solid blue when it grabs the internet connection.
IF THAT DIDN'T WORK Check the cable between your modem and the Orbi's yellow Internet port. Unplug it from both ends and firmly reseat it. If you have another Ethernet cable, try swapping it. A poor connection here will cause the amber light.
HEADS UP If you keep having this issue after outages, consider plugging your modem and Orbi into a good quality UPS (battery backup). This lets them shut down gracefully during a brief outage and prevents these boot sequence conflicts.