Last week Apple released firmware version 7.9.1 for Wireless-AC AirPort Extreme and AirPort Time Capsule. This is a security fix, so I recommend installing it right away. If the light on your AirPort recently changed to orange, this is likely the reason why. It’s just trying to get your attention.
To update, open the AirPort Utility app. You can find it in your Applications/
If you get an error message saying that it can’t update then you may need to restart your AirPort first and then try again. Just disconnect the power and plug it back in.
This update is only for the Wireless-AC routers. In other words, the ones that are tall while towers.