I remember when books like these were offered on portable red, blue, and yellow shelves. Talking about the Scholastic book faires that would come to school in the 1980s. I don't remember what the colours represented, but I remember the colours clearly and I don't recall any green, purple, pink, black, white, or orange shelves, just those three colours, so I imagine they meant something. But I looked at everything.

I think I also got "The House With a Clock in its Walls," the cat vampire one, the vegetable vampire one (I forget the names), "Tom's Midnight Garden", and other school-friendly/age appropriate YA horror, before I discovered Stephen King and Dean Koontz. (And then I never looked at YA again, until the Harry Potter books started coming out. I'm still reading Sword Art Online, which is YA from Japan; they call it LN, or Light Novels, over there, but, same thing.)