Default B&N Nook reader night mode why no black?

Hi this is really bugging me.

My phone Nook app renders the blcks correctly in the night mode. Its really white letters on black background.

Somehow when I pick the night mode in the Nook Color the night mode renders white letters on gray background.

How can I change this annoying gray to a true black? I know the NC can do it because the Kindle app does show a black background.

I tried installing the Nook app on my nook color but it doesnt allow me.
I'm using Stock 1.2, rooted, OC'd to 1.1 mhz.