Change player color glitch
The Change Player Color glitch allows you to change colors of your character on Pokémon G/S/C.
Procedure
1. Start a game as either a boy or a girl and save it.
2. Start a new game as the opposite gender as the first save.
3. Save the game, but turn off the game while it says "SAVING...DO NOT TURN OFF THE POWER".
4. When you restart, you character should be the wrong color.
Normal Boy New Boy
Normal Girl New Girl
Notes
You can do this without starting a new game by skipping the first step, but you will lose all of the Pokemon you have saved on your PC.