Loss of colour when playing any discs

Possible the DVD player is outputting in progressive scan mode. Try checking your manual to find out how to turn it back to interlace... with LG, it's either a button at the front, or a menu item in the Picture category... you could also try ejecting the disc, closing the tray and when it says "No Disc" then hold the stop button down for 5-10 seconds... see if that helps.