The purple and green tinge is from the magnetisation of the front screen. This normally happens if a child wipes a magnet across the screen, or an electricity spike somehow generated a magnetic field close to the screen. To fix it, you either need to wipe a magnet across it and 'toy' with the colours until you are comfortable with it, or find a 'Degauss' button on the TV that should make the image shake a bit and cause the magnetisation to fade.
Good luck
Owen
December 2008