Maybe three colors is a bit limiting. I'd say you need a very bright color (or pure white) for speculars, which could be common to all materials.
Is this shading drawn from life, or do you 'guess' it? In the many color versions it does look pillowshaded which is usuallly the result of guessing: concentric rings of colors. Stuff doesn't look like that IRL: look at the photo I posted above: the color zones are not rings, some transitions are smooth and some are hard.
The angle of view is much better now.
You'll have to check the linework which is very jaggy (especially the crest, both the top and the holder).
More than that, you have to think hard about outlines. Do you want/need them?
At this level of detail, they use up precious space for small detail shading, and they create a
banding festival.
I don't like obviously colored outlines either, they have no point at all, except maybe to tone down some
inside outlines, when done well.
Outlines are an abstraction, they don't exist in things. If you go for them, make them plain, dark, and outside only/mostly.
Depends on what you plan for this piece afterwards: keep it a single sprite on transparency, give it a simple background, or create a scene around it.