Since we are still voting for our two favorite hexie themes, Stashbusters and Black and White (and White and Black) prints are currently the top two.
TRUE B/W and W/B prints are just that--black and white or white and black--NO ecru, cream, off-white, eggshell or grey allowed. When viewing your stash or shopping at your local quilt shop, it's best to take your fabrics to a natural light or just take a piece of white computer paper or bolt of white fabric and place on the questionable fabric. If you doubt the shade, it's probably best to go with your gut and not use it.
Here are some suitable prints from my own collection: