|This glitch is for a home console Pokémon game.
The Shiny Shadow Pokémon glitch occurs in Pokémon Colosseum and was fixed in Pokémon XD: Gale of Darkness, which disabled the chance of obtaining a Shiny Shadow Pokémon entirely.
Like in the core series games, a Shadow Pokémon will have a 1/8192 chance of appearing as Shiny. However due to a glitch, capturing it will most likely change it into a non-Shiny version of the Shadow Pokémon. A Shadow Pokémon that appears as a non-Shiny may also become a Shadow Pokémon upon capture.
When the player captures a Shiny Shadow Pokémon, its Trainer ID will most likely change from one value to another. Since the Trainer ID is a factor in calculating whether a Pokémon is Shiny, this causes the Shiny Shadow Pokémon glitch.
In Pokémon XD, the game will generate a new personality value for the Shiny Pokémon if either the opponent or the user's Trainer ID would result in a Shiny, in order to prevent a Shiny Shadow Pokémon from appearing.