This is a colorization hack of Pokemon Red, done entirely using ASM. It takes full advantage of Gameboy Color hardware, which is much more capable than the Super Gameboy. The overworld is fully and properly colorized, and with colorized attack sprites, even battles are more colorful! In addition to color, Pokemon and Trainer sprites have been imported from Pokemon Gold/Silver/Crystal, and so has the battle HUD. If you don’t want this, the “vanilla” patch does not touch these.