Why is everything green in night vision goggles?

I can understand why we don’t see full, vibrant color as we do in sunlight. The night-vision device is recording only the infrared wavelength, so full color is not possible, as there is no spectrum of wavelengths to support it. But why not grayscale? It seems to me a black and white TV images is easier to visually decode than the strange green world of night-vision technology. Why green>