The green color family includes hues such as olive, forest, mint, pea, grass and sea greens. When dark green wallpaper is selected, it makes your room feel refreshing and cool. When dark green wallpaper is used in lighter shades, it will make your room seem larger because it feels like the walls are further away. dark green wallpaper will provide an atmosphere of relaxation to a room and is an important shade where restfulness is important. A little known, but interesting fact about green is that it is the color that is the least tiring to the eye which is the reason why surgeons scrubs are green.