Some questions regarding on post processing...

This is NOT my picture.


Thomas is a great photographer that shoots large formats. I love urban shots, and the unique colors in his photographs is what I like the most.
I've always thought that the color effects are from some type of filter lens, since he does large format.
But from seeing an example above, taken by a Lumix LX2, I am assuming that the color effect might be done by post-processing.

What kind of Photoshop plug-ins will able me achieve this kind of colors?