I think a pointy C4D would work better than the bubbles.
The blur is good at making the focal pop out (the render) but the bubbles are so big it still distracts more than the render.
Look to the piece you got and get 3-4 colors max. (Black, White and 2 other colors max!, remember) You got yellow, green blue, black white...
Plus try to work more shadowing in some areas.
3.5-4/10 to be honest.