How important was the invention of blue towards anime?
Honestly no, it's like saying that a certain type of pen led to anime and manga, or that the printing press led to their eventual creation, sure it could help make the experience much better and easier, but they aren't necessarily creation sparkers. Prussian blue just gave us a new cool looking color to use in anime and manga, but was not key in its development. Our desire and interest for storytelling along with our fascination in artistic expression is more linked to the creation of anime and manga, definitely not Prussian blue.