Rainforest Green Metallic. I think it should have been made the signature color for the Diesel since it was added to the Cruze lineup the same year the Diesel was (already in use prior to 2014 in the Corvette and Chevy pickups), and since green is the color commonly associated with Diesel labeling anyway.
Would have loved to get the ultra-rare Autumn Orange Metallic, but it was discontinued after 2013. We tried to locate, and even order, an Atlantis Blue Metallic with the Cocoa/Light Neutral interior, but ran into a situation where pulling the trigger on the buy was urgent and ended up with the RFG.