What do you mean they only recolored stories from the Flash backups? I have one of the Neal Adams Batman hardcovers, and it's all been totally redone, with new effects. Look at the new version of "The Joker's Five-Way Revenge," which is currently collected in the JOKER: THE GREATEST STORIES EVER TOLD tpb, and compare it to the version collected in the original GREATEST JOKER STORIES EVER TOLD.