if others love what you have done maybe you are just tired of the black & white- i think many of us have been where you are- finish it up- when it's done you may again love it- if you think it needs more black - i would not replace/redo the white/black blocks- i think adding a solid black for sashing/frames may be the answer- or a black/white border around it. your son is probably going to love it even if you don't.
finish it up!