Shiny Pokémon

Shiny Pokémon are very rare forms of Pokémon that are different in color when compared to other Pokémon. They are not a glitch, and in Generation II games they are stronger than their normal color brothers but in the Generation III games they had same exact stats as their normal color forms and in the Generation IV games they are sometimes stronger than normal Pokemon. The game has a way of deciding if a Pokemon is Shiny. When the Battle starts, the game picks four random numbers between 0 and 65535. If any of the numbers is less than eight, it is a shiny Pokémon. The chance of seeing one of these is about 1 in every 8192, or 0.000122%. There are a few different ways to catch them. The term 'shiny' is a reference to the sparking animation and sound effect when the battle starts.

Chaining (Gen IV)
This method uses the Pokéradar to track down chains of the same Pokémon. Here's a few tips:
 * If the bush just shakes, it is a Sinnoh Pokémon.
 * If the bush has a whitish shake, it might be a non-native Pokémon.
 * Never use it in water, caves or tall grass.
 * The bush with the same type of shake as the first Pokémon you battled that is the farthest away within a four by four grid most likely is the same Pokémon. (Grid Shown Bellow).
 * If the bush sparkles, it's shiny Pokemon

In-Game Shiny Pokémon
In-game shiny Pokémon are met as part of the main story in a Pokémon game. For example, the Red Gyarados appears in Pokemon Gold, Silver, and Crystal Versions, and in Pokemon HeartGold and SoulSilver Versions as part of a story arc, and can be caught in a way similar to most legendary Pokémon.

In Pokemon Mystery Dungeon, two Kecleon own a shop in the town square. One is a dark purple color, but it is not shiny, just alternately colored.

In Pokemon Mystery Dungeon: Explorers of Time and Pokemon Mystery Dungeon: Explorers of Darkness, there is an alternately colored Celebi, but, like the Kecleon of Red Rescue Team and Blue Rescue Team, it is not a shiny Pokemon because a shiny Kecleon has a blue stripe.

Shiny Legendary Pokemon and Shiny Starters (Gen-II to Gen-IV)
One method which is easy enough (but doesn't make shinies any easier to get) works for both Legendary Pokemon and starters... the Soft Reset. Basically, the method is to stand in front of the legendary Pokémon you will catch/starter you will take and save. If you don't get a shiny when you get your starter/battle the legendary, soft reset the game (Software Reset) by pressing A+B+Start+Select on the GBA and L+R+Start+Select on the DS. Soft Resetting can easily require over 1000 sr's (Shiny Resets), however with enough dedication and patience. One day when you battle it, it will be shiny.

Shiny Pokémon in the Anime series

 * Butterfree: The first alternately colored Pokémon to appear in the series was seen by Ash in the first season when he released his Butterfree to mate with it. (not officially a shiny)
 * Noctowl: Ash Ketchum caught a shiny Noctowl while on his travels through Johto. It also seems to be about half the size of other Noctowls.
 * Shuckle: While in Johto, Ash and co. discovered a Shiny Shuckle.


 * Gyarados: First seen in the Lake of Rage and was caught by Lance. It was also seen again during the battle between Kyogre and Groudon. It is also mentioned at the begining of Pokemon Diamond and Pearl on TV and your rival.


 * Magneton: Owned by Pokémon Trainer Jackson when he battles Ash in the Silver Conference.


 * Swellow: Winona, the Fortree City Gym Leader has a Shiny Swellow.


 * Donphan: A Shiny Donphan was known to have been shown in the Hoenn Region on Dontoe Island.


 * Magikarp: Was seen briefly in the episode "Judgement Day".


 * Dustox: Jessie's Dustox fell in love with a male Shiny Dustox and then was released similar to how Ash released his Butterfree.


 * Metagross : In the epidsode "Noodles! Roamin' Off", James in Team Rocket went out to see this strangely colored Metagross that people had been talking about, and was promptly attacked by the shiny Metagross.


 * A Ditto in "Dealing With Fierce Double Ditto Drama" was shiny.
 * Ariados: In the Special Episode "Dawn's New Journey", Dawn and Cinco encountered a swarm of Ariados as well as a shiny one using Psychic so the others could wrap Dawn and the others with String Shot.

Trivia

 * The Masuda method was named after Game Freak director Junichi Masuda, who programmed it into the game. It is an easier method to obtain bred shinies. When breeding two Pokémon who are from different regions (such as a female Milotic from the US and a male Milotic from France), the chance to obtain a shiny egg is increase tod 1/2048 from the beginning rate of 1/8192.