Nice I love the background mostly, that antialiasing goes perfect. I don't think the green is working on the face, but that's only a matter of taste. The clear green you used in the reflextions on the right side of her face and nose (her right) and mostly the violet-purple shadow you put in the chin is confusing the light direction, and make it look like if the lightsource was down-right. The reflections shouldn't be clearer than te main lightsource unless you make a backlighing composition. Hope it helps.

 This seems to be the corner of your expertise, glad to have your feed and crit for this.

I like it: The odd colorscheme of the foreground, which is nice in contrast to the warm and delicate background. Although the face seems somewhat stretched and the highligthened areas just affect the edges, it works...

In the old days one could blame odd dimensions on that the PAL/ NTSC-scene was having different pixel-ratios. 

very impressive. your skill is improving.