Has anyone else noticed a slight black staining on the delicious in dungeon box set?

I opened up my delicious in dungeon box set today, I noticed that there is a slight black staining on the box with no explanation as it was brand new and sealed in plastic.

After looking online I haven’t seen anyone talk about it, but I can kind of see it in the pictures I see online, can anyone with this box set tell me if theirs has it or if mine somehow came stained from the manufacturer.