A palette of colors on a silver plate: That is what the world's first color photograph looks like. It was taken by French physicist Edmond Becquerel in 1848. His process was empirical, never explained, and quickly abandoned. Now, a team at the Centre de recherche sur la conservation (CNRS/Muséum National d'Histoire Naturelle/Ministère de la Culture), in collaboration with the SOLEIL synchrotron and the Laboratoire de Physique des Solides (CNRS/Université Paris-Saclay), reports that the colors obtained by Edmond Becquerel were due to the presence of metallic silver nanoparticles. Their study was published on 30 March 2020 in Angewandte Chemie International Edition.