i have a 50 " vizio plasma that has somewhat muddy colors, but main problem is lighter shades have a slight rainbow effect from light to dark areas within any given scene its annoying at best . also the picture isnt as bright as you would think it should be , if i adjust the brightness or contrast the screen doesnt by any means look at all a vibrant display. its like this using any of the inputs. does anyone know what would fix this ? if it were an lcd i would think along the lines of bulb issues but being a plasma thats not the case. is there any remedies or perhaps a service code to do some adjusting or do i need a new video board or what. any help would be appreciated.thanks