I've tried and I've failed.

I didn't change much, because I don't understand my mistakes. I changed the helmet and pauldrons (I think that's the name for the gold things on his shoulders), and did some small changes to the armor. I also cut a few colors from the palette, probably could cut more. The other image is an official halberdier sprite from the game for comparison - I picked part of the colors from official sprites (skin, gold, wood). It seems to me that the sprite uses quite saturated colors and I tried to imitate that in my sprite. I don't know if I'm right or if it matters for consistency reasons. (The halbardier sprite is licensed GPL, so I hope no copyright warning here)
About chromatic greys: I don't know how to create or use them. They are created by adding a complementary color, which is probably easy to do with paints, but in digital painting it seems that it would result in small changes in hue and lowering both value and saturation, what is basically what I tried to do. For example let's take the gold ramp (copied from other sprites): Is it ok, or should the hue shift be bigger?
If someone could point me to a good understandable-by-a-noob color theory article that would explain it to me, I'd be very grateful. I've found many articles that explain contrast of opposite and similar colors, but the only in-depth one I found was on huevaluechroma.com and I understand some one fifth of it.
I'd also need some more specific advice on the shape problem - I can't fix it because it doesn't look wrong to me. (I've messed up the face, but never mind it for now)
Thanks to SwapBrain for the response and info on the browser problem.
Edited to add some stuff.