I'm not sure what sort of color gradients you have happening on this particular piece, but it is not doing it much justice. Although adding a decent sense of atmosphere, it's really bringing down the overall color quality. I recommend reanalyzing your current filters and then only leaving the appropriate ones. I do like how the background perfectly compliments the light effects on the render, so I am very impressed with that - however, I feel that your light sources could be improved on to make them a little more brighter. If possible, remove the white orb near the render's left hand as it really is distracting from the intentional focal.