I love that you are doing C64 pallette.
I do not know if you are just going for the colors only, but if you are going to make a game look like a C64 game you have to make the graphic actually look like C64, the multicolor graphic on that machine always have 2pixels wide "pixels". (the resolution is half on the width than the height so one pixel compares to 2 pixels wide for us)
Better to see example, see that everything is 2 pixel wide! https://peukalo.files.wordpress.com/201 ... bruce1.png
Of course with some genius programming people could make "high resolution" sprites for the main player by adding 2 sprites over each other, bottom "low res" with colors, and top "high red" with the black outlines.
(on C64 you can have low res and high res at same time, high res = one color only)
Like this one: http://grumbel.blogspot.se/2011/04/c64- ... prite.html
But only for one sprite because of the very low sprite limit!
But maybe you were only aiming at using the limited color palette, then ignore my post.