Heeeeelllllloooooo guys!!!!!! IT IS BLACK ON ALL COVERS!
NO IT IS NOT!!!
We are talking about the part under word Nintendo inside the red rounded part. On the two covers mentioned it is black on all the other covers it's white.
Aaaaaaaaaahhhhhhhh. Now I see what you mean. Why didn't you say so from the start. 
Well I did on page 15 of this topic:
NES game Kirby's spine's Nintendo logo is filled black while others are filled white.
Are you both yure about this? I don't see a black background on Kirby or Astyanax...
It can be tricky to spot, but it's quite clear when you have them printed out and sitting next to each other, like I do. Look only at the Nintendo logo on the spine. Most are red and white, these ones are red and black. I am positive I am not nuts. Well, not about this, at least.