The old French technique of wall mural paint, where the final effect is a Monochromatic Tone in different shades of grey, dark and light, is as old as it gets.  Reinvented or discovered during the Renaissance as a form of a more affordable painting technique, perhaps also due to limited color options that were available for painting, it's been reinvented in forms of wallpaper, posters and panel screens.  Its monochromatic tone makes it a perfect background for all kinds of decor style, from modern to traditional.  I love it with a dash of color furniture for a more contrasting and modern effect and when enhanced with a touch of brass it is simply harmoniously gorgeous.