The flashing amber light means "Do not disconnect, Shuffle is in use"
iPod shuffle is in use by your computer and should not be disconnected. If you want to disconnect iPod shuffle while in this state, use iTunes to eject iPod shuffle (or quit all applications and eject iPod shuffle from Windows Explorer or the Finder), wait for the status light to stop blinking, and then disconnect iPod shuffle.
To determine whether iPod is fully charged or charging, eject iPod in iTunes or from Finder/Windows. If the light turns solid orange and it is not blinking, it is charging. If it is green, it is fully charged.
