I'm not sure if you could tell but her face is pale yellow, being the underside of a paper that had marker ink bled through. This technique of drawing something heavily in marker then going over the back side of the paper with new lines done in pen or india I just began experimenting with during my senior year. It's a fun way to make a creative solution out of all those annoying bleedthru marker pages that waste your notebook paper.
Same process was used here:
"When life gives me lemons I make beef stew."