The PID generation method and RNG conditions of My Pokémon Ranch are at-time-of-writing unknown. Like all other Hayley trades, this is likely to be shiny-locked, and no one has ever come forward with proof of receiving a shiny Hayley Mew or Phione, but a shiny-lock has never been confirmed for sure.
Edit: Kurt, Sabresite, and Admiral-Fish discovered Ranch uses antishiny ARNG, which is the same method that causes Gen 4 Mystery Gift anti-shininess. https://bulbapedia.bulbagarden.net/wiki/Pseudorandom_number_generation_in_Pokémon#Alternative_pseudorandom_number_generator_.28ARNG.29
The PID generation method and RNG conditions of My Pokémon Ranch are at-time-of-writing unknown. Like all other Hayley trades, this is likely to be shiny-locked, and no one has ever come forward with proof of receiving a shiny Hayley Mew or Phione, but a shiny-lock has never been confirmed for sure.
Edit: Kurt, Sabresite, and Admiral-Fish discovered Ranch uses antishiny ARNG, which is the same method that causes Gen 4 Mystery Gift anti-shininess. https://bulbapedia.bulbagarden.net/wiki/Pseudorandom_number_generation_in_Pokémon#Alternative_pseudorandom_number_generator_.28ARNG.29
Details for Index 89 of normal_encount and normal_encount_rigel1 and normal_encount_rigel2 (minor differences, in raid chance)
Rewards for Index 89 of normal_encount and normal_encount_rigel1 and normal_encount_rigel2 (minor differences, in raid chance)
Details for Index 85 of dai_encount
Rewards for Index 85 of dai_encount