When you're watching the Emerald City scenes in The Wizard of Oz, a green picture may feel like a benefit. When you're watching a Packers game and trying to work out which players are which... not so much. Several issues can lead to a picture having a greenish-tinge or even being pure green.
Having a green picture can be so frustrating or disconcerting that you might forget to perform a simple diagnostic check. Before wasting time exploring possible problems with your set, confirm that it isn't the input source that is causing the problem. For example, if you normally watch the output from your cable or satellite box, try switching to your over-the-air antenna. Alternatively, try playing a DVD or Blu-ray to check that the green is indeed being created by your television set.
Check Your Connections
Different video connection types break up, carry and reconstitute video information in different ways. Loose connections or faulty jacks and sockets may mean that some of the colour information isn't getting through. In some cases, most notably the SCART cables used in Europe, this could literally mean that the only colour information that makes it to the screen relates to the green part of the picture. In other cases, connection faults could mean that the picture takes on a hue that, although it has multiple colors, is more green than it should be. Either way, check that your cables are connected correctly and, if you have them available, try using different ones.
Televisions break color information down into red, green and blue components, the intensity of which can be individually adjusted. If the green is too high, or the red and blue are too low, it could result in an overly-green picture. Some television sets have an option in the Settings menu to adjust red, green and blue levels individually. Check your manual to see if this is the case. With other sets, you may need to access a hidden service menu designed for engineers. Search online for details about the make and model of your television set, but check carefully that the site providing the details appears legitimate and trustworthy. Never change service menu settings that you don't understand.
If the problem is definitely with the TV -- the connections are fine and the color settings are as they should be -- your set may have a serious fault; particularly if the picture is entirely green -- meaning the only variation across the image is shade, rather than color. This could be the failure of one or more of the "guns" that beam electrons onto the color screen. These guns handle red, blue and green, so if the red and blue guns are damaged, the screen may be left green. Such damage may be caused by magnets near the screen, for example, from an unshielded loudspeaker -- and it could be permanent or reversible. Either way, you will need to use a professional repair service to have the set examined. Get a quote for any prospective work, as the costs may mean it is more economical just to buy a new set.