What do the different LED status colors mean on the Samsung Xpress SL M2020?

A solid green LED means the machine is on-line and ready to use, while a blinking green LED indicates data is being received or printed. A solid red LED means the cover is open, there is no paper in the tray, or a major error has occurred. An orange LED means a paper jam has occurred, and a blinking orange LED indicates a firmware upgrade is in progress.