>>57140994hot take:
each Pokémon should have multiple possible shiny variants, maybe 3-5 of them
each variant should be more rare the more different they are from the base coloration
the least-different variants should be more common than the standard shiny rate so that they're more accessible—maybe even common enough that your average kid playing Pokémon who knows nothing about shinies could encounter a Pokémon that was slightly different and then tell his friends about it at school and give them stuff to talk about and get more interested and invested in
unless they have an experienced player guiding them, most new players aren't going to find out about shinies even existing for years
but if Kevin tells you during recess that he found a Pikachu with orange cheeks instead of red, or if Michael tells you at lunch that he heard a rumor about an Aron with green eyes, then you might go looking for those, too
and you might even be able to find some of them if the odds were only something like 1/200