This is a Game Boy Color Atomic Purple with a backlit screen. I replaced the original screen on it with a new backlit, IPS screen. The original screens Nintendo used on all Game Boy Color had no backlight, which means playing in poor light or at night wasn't possible. Several companies did release a light accessory that provided enough light to play at night. For its time it worked, albeit cumbersome and certainly not perfect.

In the pictures, the left Game Boy Color has the original screen, the right Game Boy Color has the backlit IPS screen. Makes a big difference. This handheld can now be played properly at night!