If you look up army green you will see a variety of colors with that name.

Black is neutral, though if you look at several blacks from different manufacturer's placed next to each other they will vary.

Northern light is bluish and tends to wash out pale colors. Many designers recommend warm colors in brighter tones to counter northern light—pale pink, orange or yellow whites and grays. Below is a yellowish gray shown with absolute black and one of the army green colors.

You may hate it, but the yellow tone in the gray works with the green. Of course, you should always buy a sample and paint it on at least two walls in the room before committing to paint the entire room. In addition to how the color looks in daylight, you should consider how it looks at night. Warm white bulbs with a color temperature of 2700K give off yellow light that affects the colors in a room. Daylight bulbs have a color temperature above 6000K and give off blue light. Bulbs with a color temperature around 4000K give off a more neutral light.