I had the GameBoy Color version of the magnifying glass/speaker/fake joystick combo. It ran the speakers and the light off of its own pair of batteries. The speakers were an upgrade (especially for the stereo sound) but everything else was a gimmick. The incandescent bulb was too dim and housing around the screen made it darker and even more difficult to see:
Later on in early 2000s we got the worm light. LED and was powered from the link cable port. It was considerably brighter and hardly affected battery life from what I remember:
We also eventually got magnifying glasses that didn’t have the housing around the screen to darken it:
Same but I was 12 at the time so I didn’t think much about the bulb tech nor it’s color temperature. I was just like “wow that’s a bright bulb”.
Later on around 2005 I got my first piece of tech with an OLED screen: a Kenwood car stereo. It wouldn’t be for nearly another 20 years when I finally got my first OLED TV.