though i would say you should darken the brown shell lines a bit. they're almost lighter than the actual shell now. you want them to stand out, but not so much that it just doesn't look natural.
also, yes, please reduce the noise. subtle amounts look good, but overdoing it will make him look really dirty. stick to colors just slightly off from the base color so much that it isn't just a solid color, but not so much that he would be covered in static. in between y'know? looks way better than a flat color any day.
and as i've said before, try to avoid using black anywhere even on the eyes. right now they contrast way to much with the rest of the body and just pop out more than they should. make them a dark grey rather than black, even that small change would look a lot better. the red is also too poppy for my tastes, making it duller would be a lot easier to look at on that blue.
and give them some highlights too! even just a little more white on the top would add some life to him.