This procedure is also useful for that kind of change https://forums.unrealengine.com/showthread.php?76709-HOWTO-Add-new-dinosaur-variants but it is more time consuming. It’s good to make a copy in case you want the original in the future. For what you’re doing you’d need to copy the core blueprints/primal game data file, the dinosaurs’ blueprint, the dinosaurs’ random colour list, and spawn files.