Nude female figure recline quick color sketch study

Here are step by step of my figure study nude reclining lady. Just want to practice more figure and facial structure and hair on this one. Lots of time I spend on her hair and still not to the point that I want from the painting yet. I still have some work to paint more hair and such to get a good result.In my opinion, painting hair is the same as painting any object from light using light and