Yeah, I was wondering the same thing. I don't get if the grey scale is only for the web design or the phone is all black and white. Is gray the color color i can pick for the phone? What if I want a red phone? Is it gonna be a darker black phone?
When powered off it would just be a completely featureless slab. You could even write the devices logo onto the display before powering it off to do branding without redundancy.