My own choice is the just-barely-favored #2, for a lot of the reasons that have been ennumerated. It pays more attention to actual lighting sources, the depth and shading is good, and I love the night sky behind her (it works *so* well with the next page, too!). My second favorite is #5, with #6 in there at just about the same place, except it's just a little too dark for me. #1 is a little too cartoonish: the colors are good and I love the depth and richness, but it just doesn't quite work for me.
The Controversial Blue Lipstick: my first reaction was AUGH. My second reaction was 'huh'. My third reaction, especially after talking to one of the colorists who did it (a friend did #3; he was doing it more experimentally, having never done comic colors before, than as an actual audition), was, "...I really like that." His thought was along the lines of, "This is a character whose behavior necessarily draws attention to herself, but who wears a mask: she doesn't want to be recognized. Blue lipstick is *distracting as hell*." Similarly, he added blue piping to the costume (as did #4, which I liked a lot) as another draw-the-eye-away technique. I really, *really* like that.
I am *completely* torn on whether to ask the colorist to actually do the blue lipstick, because I *really* like the psychology behind it and it *really* threw me the first several times I looked at it. The last thing I want is for somebody to be thrown out of the comic at panel one. o.O
I am in agreement with those who liked the obvious toxicity of the clouds in panels 3 and 5; that needs to be addressed in #2. I'll probably end up eventually posting another final version of the colors, after I've talked to this guy about some of the changes that might be good to see.
The only awful part about this is having to tell several people that they didn't get the job.