I took a crack at the dress:
I think your light blue is a little too contrasted with the next darker blue. Its hard to add highlights without making it look too shiny.
I think you should pay attention to helm's edit, he did a great job with the colors IMO, though I don't care much for what he did to her left foot.
A couple other critiques...
1. You're brutal with the darker shades outlining just about everything. It works on her hair, but with the boots it makes them look too rounded. Same with the dress and chest.
2. Her left hand is too far toward her midsection to be resting on her hip ( which I guess is what it is doing? ).
3. The boots look like stool legs, they need to be tweaked so they have more perspective.