By changing the lightness/darkness of the filter color you change the brightness of the scene. Select a darker color and the scene is darker. Select a more saturated color and your moonlight color is more saturated. Human vision at night is desaturated depending on the amount of visible light, so you may want to desaturate the original scene before adding the moonlight color. Adjusting the saturation slider removes the original colors in the scene for a more natural look.
Night Vision mode uses the red channel to create a B/W image and applies a green filter to simulate night vision scopes.
Infra-Red mode uses the red channel to produce a B/W image. Because the image is made from light in the red spectrum, it is similar to infra-red photography. Of course your video camera likely does not record true infra-red energy, so this is only a simulation. Use Infra-Red mode in combination with Chromatic Glow for greater effect.