[shanghaichica]

I think the contrast is better on black/darker readers. My main device is a kindle so I always get them in a black/dark colour. I bought a kobo mini recently and got that in white for the novelty factor and it does look more attractive especially when you change the snap on backs. Obviously my paperwhite has a better screen so I can't compare it to that, but I think the screens on the kobo mini and my nook simple touch are similar. When I compare them I find that the nook has better contrast and I think that is partly due to the fact that it is black and that the kobo is white?

Also last year I briefly had a kobo glo in white which I compared to the kindle keyboard and kindle touch that I owned at the time. I also thought that the contrast on the kindles were better due to the darker bezel. Maybe it's just the way my eyes work.

You could go to the store and have a look at the white and the black side by side and see which one you prefer.