Well I don't know if his style is anything to write home about personally. But anyway, to be helpful look up Anthony Jones "Add Lighting to Your Lines". I can tell its pretty much what he's doing it seems.
With your guy here though he's basically doing his line art, adding base colors on one layer or separating each different color on new layers, he then adds a solid color layer, changes it to multiply and pulls it back a bit in opacity. He adds a mask to that layer and paints out where the light is hitting the form and does the correct material appropriately. He then seems to do another layer similarly for reflective light or bounce or rim light. Lots of control.
