The blue color family includes hues of sky, royal, midnight, baby and powder blues. Since blue is the coolest of all colors, dark blue wallpaper is the most receding and serene which makes it a popular wallpaper choice. dark blue wallpaper will make a room appear more spacious and airy. Using lighter colors against a dark blue wallpaper will make the furniture or furnishings appear more luminescent and really stand out. An interesting fact about the color blue is that people associate stability and leadership with this color and that is why you will often see important documents like graduation certificates bound in blue.