While having matching palettes is great and all, I feel it's fine to have some variation to them. The actual Pokemon Sprites don't keep the same palette for the entire Evo line.
The Bulbasaur family is looking a little too blue to me.
I personally lean more towards canon shiny colors, unless the canon shiny is just a darker shade of the same colors like Garchomp. And I think Black Charizard looked better than the yellow. Shiny Mega Charizard should also keep the two-tone style like the normal sprite, rather than all red.