Do you mean when you tap the Library icon, then tap the (generic) book icon all the books have the same blue icon? If so, that's odd. Unless you are looking in Storage (pull down menu top left) within the Library interface?
On mine I see 3 books across and as many as I have down. All show a cover of some kind, although it takes a moment for the covers to appear, and I see the generic blue until they do.
