Looks cool man! If you're looking further into color, perhaps may I give some slight advice? When you're highlighting, try not to use white. With this red for example, as you're getting lighter, shift the hue to orange, then perhaps even bright yellow for hotspots and make it nice and shiney ! Check out the red on this hellboy piece to see what I'm talking about [link]. Same applies for all the colors, if you just highlight going towards white then your piece will look off, muddy.