I've used Warm&Natural black batting in a number of quilts - all dark, with no problem. Feels and quilts just like the cream and white W&N battings.
I was in Joann's a couple of years ago. The manager knew I was a quilter and asked if I wanted to buy the bolt of black batting. Apparently, it was just sitting around and not selling. I ended up buying it for less than $15 bucks - for a 40 yard bolt. I've only got around 3 quilts worth left.
But I wouldn't use it behind a white/very light colored top.