There was also the backlit Gameboy Light, which was only released in Japan. It was essentially a Gameboy Pocket with a electroluminescent back-light. It glowed green like those old Indiglo wrist watches.

I've got one, but sadly the LCD has a bunch of dead lines. Apparently, that can be repaired pretty easily.

https://en.wikipedia.org/wiki/Game_Boy_family#Game_Boy_Light