i think it is safe to asume that he looks cool!
If you want to try to add a bit mroe deapth to him, try adding in some inks and highlights. for the skin, try getting black ink, warter it down a fair bit and wash it over to shade the 'groves' in his arms, then pick out the more rasies areas again with that green.
as a genrall painting method that i find works really well for more or less anything you paint try this
paint on the basic colour, blue, green, light flesh colour, what ever
give it a wash with eather a darker colour thined right down or if it is a dark colour already use black ink
go over the areas that are not the deeper groves with the original colour
finally, if you fancy picking out some detail, highlight the higher areas with a lighter shade of you basic colour, or mix the colour with bleached bone. I find that bleached bone is better then skull white when you are ligthening a colour as it seems to help keep the colour rather then bleach it out... if you follow.
If i had a camera, i would do a proper tutorial of a few difretn examples. I will do when i get a camera... im poor
but yer, keep up the work dood!