Color of ghost imaging Deyang Duan, Shaojiang Du, Li Yan, Shengshan Jiang, Yuanyuan Liu, Lu Zhang and Yunjie Xia Eur. Phys. J. D, 68 1 (2014) 11 Published online: 23 January 2014 DOI: 10.1140/epjd/e2013-40409-6