Yeah, I answered four questions when you first posted this and realized it was the same thing over and over, just with a normal character and one ever so slightly darkened. The darkened characters weren't even well done or well thought out. It just looks like an amateur messed up the levels or something.
Very boring. You should put more effort into this if you want to hold the attention of busy strangers.
EDIT: It's a neat idea in theory. I wish you'd test different colors instead of just lighter/darker. The stereotypes of light = good and dark = sinister are already well known and over-abused. Make some changes and you'll have a thesis to be proud of. Good luck either way!
'Cuz life is full of your regrets, and I should be one...