Study more lasso tool coloring, with b/h and slight blur, it would go well with the current line work.
If you don't know what it is, you can see it in today's comics. Color blocking, then picking the parts of the colors with lasso tool and making highlights by changing the color brightness, hue... You get a clean shading that you slightly blur to blend the tones. Make highlights on the parts of the body where the light strikes.