If the color stays yellow, that sounds like a loss of blue. Yellow is a combination of green and red. White is a combination of red, green, and blue. If you are not able to see red and green separately, that sounds like a control problem. You could try resetting the scanner. Be advised resetting the scanner will erase programming. Turn the scanner off. While pressing 2, 9, and HOLD simultaneously, turn the scanner on. If that doesn't work, you can try reloading the firmware. If scanner still does not function correctly, you can remove the case and try reseating the plug going to the display. Is the scanner still under warranty? You can also send a message to Joe Bearcat, the Uniden rep, asking him for suggestions.