123 colours holy jesus

and i don't think those hands work too well, they do look somewhat webbed and amphibian if that's the look you are going for but they don't flow correctly with the arm.
my suggestions for a few improvements, especially in the hands.

also reduced it down to 40 colours, you have quite alot of readable detail for such small sprites

oh and personally I'd advise against such strong background colours, it's eye burningly vibrant, and if you pixel with that BG tone it could effect your perception of contrast and colour intensity/saturation etc.
and most your pixels are really strong, just things you should concentrate on, colour palette. and also avoid dithering, your robes looks nice but the torso area doesn't benefit from that dithering, you might want to clean it up a bit, anyway hope that helps

Edit: also that style of isometric is called oblique if i recall, and its most notably seen in the Ultima games, it doesn't adhere to perspective in the traditional sense, but the main benefit (and main reason it was used) is it required less angles to render and animate, only 2, versus 3 if they mirrored on the X axis, FFTactics and the like did a similar thing but with a more correct perspective, also 'oblique' style isometric perspective is 45degree lines as opposed to 30 of standard 3 quarter iso?
Edit II:
thought I'd take the time to help with some pointers and observations about Isometrics in pixel art, (also remind myself of what I studied awhile ago, I even made a primitive ISO engine awhile ago)

there are the major forms of ISO, 3/4 is most common form of isometric projection in games, I also elaborated some methods of fitting the tiles into the grid, hope its self explanatory, also did view of all the planes you can create independently and then align in your engine with a offset grid, It's rather complicated, pixeling Iso is easier than actually making it work i can tell you

I also showed how your character would fit perfectly into Ultima style of (quirky mixed) perspective, you need to rotate the sprite by 90 degrees to get him on the other angle. The exact same principle would be true of the remaining 2 angles, but you need to do a back view for those. Hope you and other's find it helpful, probably better examples around I could've just linked to, but oh well

Edit III:
also quickly did this, man i gotta spend more time doing my own stuff

noticed the straight line of pixels, i can see what you were trying to do with the perspective, but it looks a bit strange, and to have the effect of perspective darkening the bottom would help reinforce its depth and separate it from the same plane as the top of the character, rather poor/rushed edit but hope it conveys what i mean. probably should have a crisp outline to separate it just make sure its contoured correctly, and darkening the shading at the bottom would help (my edit makes the wings fuse with the body) also avoid adding extra colours you barely use, and combining 2 shades or making one darker can make them justifiable, but too similar and they have little point. but 36 is a much better colour count than 123
