>>57964924
stadium had it right, but it should maybe be something like a pokemon can be hue shifted by (up to) like 15% in either direction including shinies. this way you could have a very wide range of semi realistic variance in pokemon colors
for pokemon like blissey where said hue shift just gives them the already available shiny, they should get a new shiny (this should've happened years ago anyway though)
you could even take it one step further and have individual elements of pokemon be shifted in different directions instead of one massive jump