I was thinking along the lines of putting something like a translucent black over white, e.g.
Taking a tube light and putting a translucent black film on top of it, you'll see a black colour but white is shining through it. In my lighting class, we have all sorts of coloured film that we slide on top of a stage light, and one film is a black one, when you put it on, it give a black effect with white shining through it. Giving a shaded effect.
I was just wondering whether they could reproduce that? not a solid black but translucent on white.