The flat skin color never looks realistic. 1) Try searching free stuff for a desent texture and the MAT file to turn him All White. 2) Then work with the lights (check the tutorial section or download some free sets - Traveler has some EXCELLENT skin tone lights at RDNA). Lights play a big part in getting a good skin tone. 3) Also like SamTherapy says you need a good bump map; I usually play with them or create my own (grey-scales of the actual texture)