Hmm, where to start. You are essentially at point A, and are asking how to get to point Z. There really is no way besides going through B, C, X, Y, etc... Honestly I don't have the experience and skills to really lay this out for you, but I can tell you to start smaller (in terms of canvas size and expected results). Your current sprite is not only flawed in it's colors, but also in it's anatomy, shading, posture, lines, forms, everything. The colors on those SF sprites are certainly vibrant, but they look so good for many reasons, not only their colors. Simply modifying the colors on your current sprite could never get the same dynamic look because the shading and lines are goofed up.
Here are my two best suggestions:
- Shrink your Samurai guy down to 1/4 or 1/2, and get some help here ironing him out.
- To animate, start with rough forms, sketches or blocked out silhouettes of the entire animation, and refine those into clear and well timed animations. Then go back and add in the details. Those street fighter animations were first rough sketches.
I know you probably really want to see your Samurai guy animated, but it's a monumental leap from what you have now to what you want, and it will only result in disappointment.