I don't have a digital camera these days, but skin has always been one of my specialities. I use Reaper Master Series paints, but I think I can give a rough approximation with Citadel equivalents. I also thin my paints to almost ink-like consistency, so the highlights blend quite smoothly.
For skin, I use...
-Black undercoat
-Scorched brown base
-Dwarf Flesh highlight 1
-Elf Flesh highlight 2
-Skull White on the brows, bridge of the nose, and the cheeks.