Yea, the face needs more contrast. But be careful about where you stick those blues/purples. They're needed in the shadows/boney areas of the face, but I think the fleshy parts--the cheeks, the neck, etc, actually need more warmth to them (orange and pink).
Here's an awesome conceptart.org thread that might help!http://conceptart.org/forums/showthread.php?t=125491
Also, what app are you painting in? You might find more intuitive blending control if you play around with PaintTool Sai or ArtRage, rather than photoshop/gimp.