One Piece databooks explained: Red, Blue, Yellow, Green, Blue Deep
Red and Blue (2002) set the pattern: Red profiles the early cast with Oda's notes and early sketches, Blue maps the world, its islands, ships, and systems, and both carry the kind of small canon, ages, origins, planned designs, that the manga never states. Their early date makes them East Blue and Alabasta-era documents, valuable as much for what Oda thought then as for what remains true.
Yellow: Grand Elements (2007) extends the world coverage through Enies Lobby's era, and Green: Secret Pieces (2010) is the fan favorite, collecting Oda's notebook material, early versions of famous scenes, rejected designs, and the story's scaffolding made visible. Blue Deep: Characters World (2012) restarts the character file for the post-timeskip cast and is the last of the bound databooks before the Vivre Card system took over the reference role.
Oda's hand is the value in all five: the databooks are where early Luffy designs, alternate Straw Hat concepts, and his explanations of names and models live, which is why Green in particular is quoted across the Library. Viz published Red and Blue in English in the line's early years (as One Piece: Red and Blue volumes), leaving Yellow, Green, and Blue Deep Japanese-only, the standard asymmetry of this franchise's reference shelf.
Import advice: the Japanese volumes are inexpensive used in Japan and dense enough that even art-and-diagram reading justifies them for non-readers, Green first, then Blue Deep for the modern cast. Confirm the obi and any bundled extras in listings if paying above the common price, and shelve them with the Color Walks, where they form the reference spine of a One Piece collection.
