Suppose they decide for the final battle in Naruto Shippuden they give Naruto's rasengan it's manga color like they did in The Last, then keep it that way for all subsequent Naruto media. In the inevitable Boruto anime Boruto's chakra will be blue but Naruto's chakra remains yellow, and Sakura's chakra green like it's supposed to be. Everyone now has unique colors for their chakra like in the manga, I think it's more interesting that way instead of everyone having blue chakra.