Its evident to me you have a good insight as what a ''good painting'' should have. Your color is good if you want to maximize it add complementary colors.......Also dont forget about texture it can add a life like quality that would add alot of alluring appeal to this subject alone. Also remember that tones in your background shouldnt exceed 5 on the value scale i think your is close to 8. this is where complements come in handy
This advice is by no means a definitive ''way'' in wich to express your self, just advice. I think your on your way
have a good one!