The drawing is pretty solid, but the colors don't work, imho.
I find that the best way to learn anything is to copy something as exactly as possible, so I recommend copying the artwork that inspires you, color-wise. Since this is based off the Rosie the Riveter WWII poster, that would be a good place to start.
http://imgc.artprintimages.com/images/a ... 13D00Z.jpghttp://2.bp.blogspot.com/-NQ6MKyZtBt8/U ... s_Drea.jpghttp://archive.ccm.edu/Rosie/images/WeCanDoItPoster[1].jpg
Notice the contrasts in values on the skin itself when you squint. Now squint at your own drawing and notice how flat it appears. Same thing with the shirt and hair.
If you're having trouble seeing what I mean, convert all images to grayscale and see what I mean.
And back in color, notice the subtle shifts in hue, shifting from warm to cool colors.
Your's is almost like a Super Friends cartoon. That's not necessarily a bad look in itself. There are artists who do great things with flat colors. Check out howardshum's or Herval's work sometime.
But I think your piece comes off as confused and unsure because it's straddling that line between painted and flat colors.
Color serves multiple purposes - from decorative to descriptive. Make a decision to how you want to use it. As with line, when used descriptively, it can describe the forms your viewer sees and serves to unify one portion of the image with the other.
Your drawings skills and draftsmanship are good, now just up those color skills
