* More variation in hue and saturation throughout each ramp (in particular you are currently conveying a grey skin tone because your dark skin tone is uncontrasted, not red/brown enough, and the same saturation as the 'light' skin tone)
* More contrast (using GIMP or Photoshop Contrast/brightness tool will give you a general idea)
* make the pose meaningful, like some sort of action is being taken, and work out the tension of each individual limb in relation to each other, starting from the ground