I adore how the Yoshi colours are handled in Yoshi's Island - you can't select which Yoshi colour to play, but each stage has a Yoshi colour assigned to it because the Yoshies are swapping out duties. It's such a cute detail for worldbuilding by making it so the game's story is a team effort rather than just whichever Yoshi colour you choose on their own, and because of that I think I actually prefer it over the Yoshi-selecting feature added in Woolly World.
Still, we don't necessarily need this.