Render:

Here is the result using this simple solution for lighting without any kind of adjustments or fine tuning...



... and here you can see some different results after some adjustments using the built-in tools under the Render menu for color, brightness and contrast in ZBrush:



Don't worry about the self illuminated look of your model in the viewport. This is caused by the parameters in the skin shader...



... because after you hit the render buttom everything looks nice again :)