Shiny Pokémon are a rare variant of all Pokémon in Pokémon Vortex. All Shiny Pokémon in Pokémon Vortex have a 25% HP boost (Level 100 Pokémon have 500HP instead of 400HP).
They have the same sprites and same colors as Shiny Pokémon in the games. For example:
This Shiny Munchlax is a different colour. However, you cannot catch a Shiny evolved Pokémon, as all evolved Pokémon can only be caught in the Normal Variant. Shiny Legendary Pokémon, however, can be caught.