How did you get so many colors into this? o_o
There's a lot of color optimization that could be done, here. ^^ Maybe try using a program that counts your colors and shows your colors and find a way to merge colors that are very similar to one another. THEN you can try fixing it up. A smaller number of colors is much easier to work with. :>
Was it maybe resized or something?
A lot of those colors seem to be transparent pixels 0_o
not sure how to get rid of those (tried to clean up visible ones earlier and invert selection to the area around the character just in case)
It's not resized. I also use artstudio for iPad (for all my just about all of my digital art), and I will never use my laptop to make art of any kind.