I don't care for this selective color technique -- I don't see what that adds to the photo.
To me the interesting part of this photo is the way the shadow of the blade is falling on the building. I would've tried getting in closer and capturing that. Just an idea...
Beautiful capture. You did extrememly well with the selective de-saturation. The blue sky makes for a nice background for the windmill and helps it stand out better. Good job.
If I may be honest I think I would have liked it more if the whole shot had been b/w or in colour, this selective desaturation doesn´t appeal to me personally and also draws the attention to the sky instead of the windmill wich is presumably the connection to the theme "wooden". Having said that though I still think this is above average in this challenge, I like the composition.
I really like the selective desat on this shot. The only complaint I would have regarding the challenge, is it would be nice to see the color of the windmill, and the wood showing through where the paint is gone.