I don't see why a white couldn't be incorporated... Actually, what I saw in my mind's eye was a gradation from very light grays down to blacks. But I would think a deep burgundy or deep olive green in sashing or border would make a rich look.
LOL!!! Hey, I've never been accused of having great taste and talent in putting fabrics together. Though, I truly love the colored samples you showed us, too. I love anything with cardinals.