You must use a Game Boy Color system for this code to work. When the words Game Boy Color flash across the screen when you first turn on the system, press the following buttons to change the colors of your game.
B and Right - This will turn all of the light colors dark and all of the dark colors light.
B and Left - This combo makes the colors go black and white, as if you were using an old Game Boy or Game Boy Pocket.
A and Right - This makes all of the colors have a green tinge, as if it is spring in the game or you are playing Pok�mon Green.
B and Down - This makes all of the colors a light brown as if it were autumn in the game.
*When you set the colors to Autumn, if you enter Rock Tunnel all the characteristics of the cave that were previously hidden in the darkness will now be visible. -Ryan*
B and Up - This turns all of the colors into a dusty brown, darker than the autumn brown.
Down - Gives everything pastel colors.
Right - Turns every color into Christmas colors, red and green.
Left - Changes all of the colors to blue.
Up - This gives everything a chocolately color.
CLONE POKEMON
Set up a trade with the game link cable. Make sure one Game Boy has a Pok�mon that will not matter if it is deleted. This would mean Magikarp, Ratatta, etc.
When the person with the good Pok�mon, such as Mew or the Legendary Birds, screen says "Waiting...!" there will be a very small pause. The person with the good Pok�mon should shut off his Game Boy instantly at this time. The other person may now turn off his Game Boy.
If you did the code correctly, when the game is turned back on, both people will have the good Pok�mon.
This code can only be used if you have an older universal link cable where there are three heads connected to a single wire.
LINK CABLE FUN
Connect all three heads to three different Game Boys with each Game Boy containing a version of Pok�mon. All three go into battle as usual, and when you enter, everything is wrong immediately. Game Boy A is fighting Game Boy B, while B is fighting C! When a Pok�mon dies, the next Pok�mon is glitched, and the entire experience is always extremely slow. It gets confusing at times, so make sure to pay attention!
SAVE YOUR POKEMON
If you are thinking of restarting your game, do this little trick first. Put all of your important Pok�mon into Stadium boxes on your Nintendo 64. After you restart your game, go back into Stadium and retrieve your Pok�mon. That way, you can have two of all the important Pok�mon, such as Mewtwo, Mew, and the Legendary Birds!