Things You'll Need
Instructions
Insert Pokemon FireRed into the Game Boy Advance&'s socket and turn on the game.
Press "Start" when the main screen appears. Press "A" and select "New Game." This will completely erase your previous saved game, so be sure you want to continue before proceeding.
Continue to press "A" through the dialogue with Professor Oak, including selecting your gender, your name and your rival&'s name. At the end of the introduction, you will end up in your room.
Exit the house by going downstairs, then save the game in front of your house.
Head north to leave Pallet Town. You will be stopped by Professor Oak.
Follow Professor Oak back to his lab, where he will give you a choice of a starter Pokemon: Squirtle, Charmander or Bulbasaur. Pick one, then check to see whether it is a different color than its normal form. If it is, you have a shiny Pokemon.
Turn off the game without saving if your starter is not shiny. Restart the game and repeat Steps 5 and 6 until you get a shiny starter.