I-It might help if somebody made an edit to actually
show him how reducing colors and increasing contrast properly can still portray the style he is going for, in a cleaner way, thus is what I've tried to do here (left is mine, right is yours):
It's obviously not great or anything but as you can see, he is still clearly soft white, but doesn't use several meaningless shades to blur it up. You can also see that I've modified some other things, such as hue-shifting the palette to look more appealing (
I'm sure this has been linked already, but take special note of the "Hue-Shifting" section), edited some pixels here and there to generally look neater, (poorly) attempted to clean up some of the shading, and most importantly, reduced the amount of shades and took full advantage of the few colors that
are there while still trying to convey the same things.
This is just to give you ideas, of course. We STRONGLY encourage you to experiment and at least
try re-shading it with a smaller, more contrasting palette on your own, because even if you think that having more colors makes it look better, it honestly doesn't; it just makes it look blurry and unprofessional.
Another advantage to having a smaller palette, is that it makes animating sprites MUCH easier, because you don't have 1,000 colors that you need to apply to one frame. Having less colors is actually more professional-looking, too, because it shows that you have the skill to make good sprites with more-limited resources, for lack of better words.
Looking forward to seeing what you can do! I could be missing something here though, haven't kept up with the thread that much. Just incorporate what we've said in your own way and we'll help you achieve sprite greatness, or something!