At first - even in such drawings the air perspective is needed. The more distant object - the less color saturation and tone. So you'll get the darkest - a shadow part of right elbow and the most colorless - the shield and a tail-tip. Just pull some blue in shadows and you'll get profit Also there's a lack of definite cast shadows on the body from arm and mandibula, that equalize planes and makes figure flat Hope, this helps you
Looks crisp. If this is representative of what you *like* doing, maybe send your portfolio to the larger roleplaying & collectible card game publishers. The look is there. I think you'd get some commissions.