I go a different way here. I think the graffiti IS the subject in the image, and it shows better in the color image. The black and white image is incongruent because it looks like you are trying to process the photo to appear archaic while the modern graffiti keeps pulling the viewer's mind back to the modern world. I think you need to process the image to reinforce its strength--colorful, modern graffiti juxtaposed against old world stone.
I would also consider straightening the image out a bit--possibly using a warp, skew or distort. By doing this you could straighten the window ledge at the top of the image (make it parallel to the top of the frame) and the bottom of the door.