With the 2011 Geneva motor show only a week away, Citroën has published photos but very few details on three new concept cars based on the firm's production models that it plans to reveal on March 1. The design studies are the C3 Red Block, DS4 Purple and the C6 ‘Noir et Blanc’. Starting with the C3 Red Block, the French firm's supermini sports a bespoke matt grey paintjob with red accents on