Once configured, it is not normal for the AX to blink the amber light. It should be green. If everything seems to be working OK, a blinking amber light may simply be an indication that a firmware update is available for the device.
If you want to pursue this, open AirPort Utility, except this time click on Manual Setup.
Click on the amber dot on the summary page to the right and another window will open with explanation about the flashing light. If there is a firmware update available, you can click to update your unit and the light will turn green.
If you do not want to pursue this, then pick up a sheet of small round stickers at an office supply store to cover up the light. It may take a few layers to keep the light from shining through.