The original had dull grey skies and poor color. However, while I was trying to clean this up, I accidently selected negative. And, I thought it looked much more interesting.
Personally I am not sure whether I like the "negative" treatment, but it's effective at emphasising the structure and isolating it within the frame. The curves fill the frame well.
Interesting effect... you dfientely "rescued" the image, if the lighting and color were not rigt. I've used use myself BW for the same purpose quite a few times. Good idea for the theme, and the treatment gives it a very graphical feeling.