Hai /w/ I really love this wallpaper but I feel it was not finished, if an anon could help me fix it that would be great

Here's what I'd like to be done (please and thank you):
Make charmander, bulbasaur and pikachu's hats, eyes and mustaches the same as squirtle's
Also fix pikachu and charmander's colour to a more vibrant yellow and orange and fix pikachus stripes/ spots and cheeks to a more suiting shade cuz the original ones seem dull
Thanks again