My preference is for image A. I feel that the texture of the blocks, compared with the flat colour of B, make it look more authentic as a statue. As well as this I guess the two colours of green are more aesthetically pleasing to me, giving a range of tones and making an interesting image. B looks simple with only the one tone though the two colours do, at first glance, give the impression of  structure and acts almost as an outline to frame the green. Image A simply looks natural whereas B is to me more artificial so this is the main reason why my preferance is for A.