This tint of green may just be one of the chips going out(There are three chips: red, green, and blue.). You can buy these for about $80-$100, but sometimes they are hard to come by(depends on where you are). You may also try to readjust the screen from the back. If you look in the back if you remov the wood that covers the back of your TV, there should be about 6 little knobs you are able to turn(Focus, red, green, blue, tilt, or reset...i think).try that...
It also depends on however long you have had this TV. It this time: you may also want to buy new resistors, for some of them may just blow out right after you fix the chip.(they are about 50 cents-1 dollar).
Hope that helps