May be you are wondering what this is ...
Its a sculpture, called "Cheminée d'aération", made by Raymond Moretti, standing in La Defense in Paris.
May be you already saw a picture of this colored thing on flickr. I had seem some photos from this sculpture before my trip to paris (asking myself "What is this?"), but did not know, that its standing in La Defense. So I walked around there and saw it accidentally, and remembered the photos I saw.