What legendaries can be found shiny by soft-reset

From the Discussion page of Pokemon Outbreaks (in regards to how to reset the swarm):

Actually, any sort of reset will work, provided you have not already saved on that date. I've taken advantage of this multiple times. If you save after the date changes, though, even if you haven't yet inspected a board, the swarming Pokémon will be set in stone. --AndyPKMN (talk) 14:16, 7 May 2011 (UTC)

Pokemon outbreaks are set by the date, lasting that whole date only after the swarm for that day has been set and saved to the cart.

Each unique Pokémon sprite has exactly one normal palette and one shiny palette. However, some Pokémon have more than one possible sprite, due to gender, variants, or alternate formes. Each of those can have a different shiny palette.

For example:

• Frillish♂ is blue, but Frillish♀ is pink. Shiny Frillish♂ is teal, while shiny Frillish♀ is salmon pink.
• Basculin can appear as red-striped or blue-striped. Shiny red-striped Basculin has an orange stripe, while shiny blue-striped Basculin has a light blue stripe.
• Shellos found in west Sinnoh are pink, but Shellos found in east Sinnoh are blue. Shiny Shellos are salmon pink in west Sinnoh, and cyan in east Sinnoh.

Generally speaking, if a Pokémon can be found in multiple different colours, its shinies will have different colours from each other.

Further, some shiny Pokémon's evolved forms have very different colour schemes, even if the original Pokémon all had the same colour.

• Shiny Charmander and Charmeleon are yellow, but shiny Charizard is black. (A shiny Charmander will always hatch yellow, and when it evolves to Charizard will always turn black.)
• Shiny Magikarp is gold, but shiny Gyarados is red.