In HeartGold and SoulSilver, there is a red Gyarados that you have to either defeat or capture at Lake of Rage. Other than that, there are no games that do that.
www.veekun.com has easily retrievable shiny pictures of all Pokemon in all games that have shinies in them.
Since the 2nd generation of Pokemon games, shiny Pokemon have randomly appeared. The chance of finding a shiny Pokemon in the wild is 1 in 8,192. In the 4th generation, they introduced an item that can increase the chance of finding a shiny Pokemon.
You do not need to go to the Pokemon league to get shinies, you can get shiny Pokemon anywhere, but they are VERY rare, and if you are playing Red, Blue, or Green, they are not in those games.
"Yes the code is to make all wild Pokemon shiny so when you catch it will always be shiny even when you trade it" *I AM IMPROVING THIS ANSWER* No, they won't be. It's a lie. There is no code (yet) that makes Pokemon PERMANETLY shiny no matter what you do, I am sorry... =(
No, you don't. Shiny Pokemon appear in Pokemon White version like every other Pokemon game, you can get them through breeding, a legendary could be one, or you could find one in the wild. However, using the Masuda method, which is breeding Pokemon from separate languages, it is more likely to get a shiny then in past games.
...shiny Pokemon are always shiny... ._.
If you catch a shiny Pokemon, it will always be shiny. You cannot make a normal-colored Pokemon into a shiny Pokemon.
The only way to get a shiny pokemon is if you find it as shiny. Shiny pokemon are sometimes up for trade on the GTS, but not always.
No, the shiny Pokemon stay shiny always. If the shiny status was a hack they may lose their shiny status, esp. if they get the pokerus
Yes the same way you get shiny Pokemon in the other Pokemon games is how you get shiny Pokemon in heartgold. There is a free shiny Pokemon in the lake of rage.
Shiny Pokemon are completely random in all Pokemon games. Just battle as many Pokemon in the wild as you can, always have a bunch of pokeballs on hand, and never use repels.
Use the shiny Pokemon cheat code. That keeps the Pokemon that hatches shiny.
no
Yes, shiny pokemon can be breed. However, breeding shiny pokemon does not increase the chances of having shiny offspring, except for in Generation II games.
yes
Unfortunately, shiny Pokemon only exist in games that aren't red/blue/red sorry
pokemon always stay shiny. They never change, no matter how much you level them up, or when you evolve them. For as long as it lives, (Which is always, they don't die.) it will be shiny. Even if you trade it. Always. Hope I helped! :D