Do you have an SP and an old gameboy game? put the game in, turn it on. the first thing you see: Nintendo. at that screen, press any of the arrow buttons. did it change color just now? try holding A and pressing d pad buttons. a new set of colors. now hold b and do it. another set! i found this out with Dr. Mario. It's a lot more fun with games like Pokemon Blue or Red, games like Yellow and Gold it might not work for. try it and reply it!

I think the SP instructions tell you this. It was standard fare since the GameBoy Color came out. Had to do something for the original GB games.

Man, I don't even have a GBA anymore, let alone a color...

I keep my GBA around if I feel like going back and playing an old Game Boy game once in a while.

I remember this trick. I think it was possible to turn everything a weird inverse color style, which I had some fun with for a total of five seconds but in the end I preferred the default color schemes.

The alternate colours made my eyes hurt.

Bloody everything makes my eyes hurt.