great shading begin. keeps it smooth where it needs too be smooth and detailed where it needs to be detailed. I'm not sure it the dithering on the arm/back is needed since it creates a bit of texture against the head, which shows that this piece would mostly work without dithering. The palette is great also. No colour sticks out, except the brightest blue maybe (the last blue before the grey which is followed by a green
I should just have started ps and got the hexcode -_-) which looks a bit too saturated. But when you desaturate it, it could harm the gradients with the highlights on his arm, so I guess you might wanna saturate the second brightest blue a bit more or just let it be as it is
Im definitely looking forward to seeing this finished