A Pokémon Yellow Romhack
Everything about Yellow you remember, running on the battle engine you actually want.
Chromatic Yellow keeps Kanto's map, story, and 151 Pokémon, then modernizes the machinery underneath. Damage is decided by a full Gen 6+ type chart — with Steel, Dark, Fairy, Sound, and Light added as real attacking types — and each move has its own physical-or-special category instead of being locked to its type. Special Attack and Special Defense are separate stats, EVs and critical hits follow modern rules, and any Pokémon can Terastallize once per battle to change its type on the fly.
On top of the engine sits a complete content pass: the entire move list was redesigned so every type has a full damage ladder, and every trainer in the game — from the first bug catcher to the Champion — was rebuilt with a deliberate moveset and smarter AI. The guides below walk you through all of it.
And none of it is forced on you. A new MECHANICS entry on the in-game Options screen lets you switch three of the headline changes on or off at any time — the choices save with your game.
Three spoiler-friendly field guides to what's changed and how to play around it.
Every Gym Leader, the Elite Four, and the Champion now field full six-Pokémon teams with a dual-type identity, smarter AI, and a Terastallizing ace. Full rosters, movesets, opening gambits, and the ace-Tera table.
The ~300 ordinary trainers of Kanto, all given real four-move sets and type-aware battle sense. How the new trainer AI thinks, which classes to respect, and a route-by-route run-through from Viridian Forest to Victory Road.
The 225-move overhaul explained: a full power ladder for all 20 attacking types, physical and special, so your STAB always scales. Retype callouts, the new-type attacking lines, and team-building tips.
Searchable, browsable stats, EV yields, evolutions, locations, learnsets, and TM/HM compatibility for all 151 Pokémon.
Every trainer battle in the game: class, location, party, each Pokémon's level and types, and the exact moveset it fights with.
Every move in the game: type, category, power, accuracy, PP, TM/HM slot, and the exact chance for any secondary effect like burn, flinch, or a stat drop.
Chromatic Yellow ships as a patch you apply to your own Pokémon Yellow ROM.
Because this is a modification of a copyrighted game, only the patch is distributed — never a full ROM. You supply a legally-owned copy of Pokémon Yellow, apply the patch, and play the result in any Game Boy Color emulator or on hardware via flashcart.