You can use an action replay code for make all Pokemon shiny.
Chat with our AI personalities
When I was playing Pokemon pearl a women in a house told me that the shiny pikachu is yellow.
If it is shiny or Pikachu coloured then it is
I don't there will be an other date, but a pikachu-colored pichu is actually a shiny pichu.So clearly you have 2 ways left.Either you use a AR code for shiny wild Pokemon or you be super lucky and find one.(chances of getting shiny Pokemon in the wild: 0.001 sort-of)
Breed a female pikachu that is holding a light ball, and a ditto at the daycare center. Then if you are really lucky, a shiny pichu with volt tackle will hatch out of the egg.
You can't; the odds of finding a Shiny Pokémon are 8192 to 1, in most cases. But they weren't introduced until Generation II, so having one on Yellow is impossible.