Connected with the other two, adds atmosphere.. very late in the event. Military nightscopes have a green screen because it is the wave length that human eyes are most sensitive to. So this has a clandestine look. -tv
Pete, if you darken the original and set the noise for monochromatic, you might be able to avoid the banding and the magenta noise that has crept in. I suggested darkening because I've found that adding grain seems to lighten the dark tones.
--Mary Anne