Did you try this one in pencil first? Understanding the shading with pencils would really help getting it right in color. One thing I do with colored pencils is add the lightest color all over first, then build up layers going darker each time but be careful, some yellows have a high wax content and eventually they won`t layer anymore. I see you graphed off the paper, something I often do to get everything right, works for me. Please....flip your pics, just makes things easier.