These hardcover books can identified by their distinctive covers which had a different background for each character. Spider-Man: Red with a web motif, Avengers: Green with a repeating A in a circle pattern, Daredevil: Red with a Repeating Double D pattern, Fantastic Four: Blue with a repeating 4 in a circle pattern, Thor: Blue with a repeating Hammer in a circle pattern, and X-Men: Yellow with a repeating X in a circle pattern.