Awesome piece! I really like your coloring. I especially like how you colored her hair. You always do such a nice job. ^_^ Her costume has a very interesting design! The thing hanging from her collar looks neat. XP Her hair ornament is also very cool.
For improvements, I would add more depth to her face. Compared to the rest of the image, it looks a bit flat. Other than, everything looks good. Spectacular job! ^_^
I can see why the coloring job took you all day! It looks amazing! Very good work! ^^