Can anyone guide me to a publication in which eumelanin and pheomelanin are synthesized side-by-side: one reaction involving L-DOPA and leading to a dark brown to black pigment and a similar reaction involving L-DOPA and L-cysteine leading to a yellow to red pigment? It can be non-enzymatic or enzymatic reactions, but any experiments that clearly show that the presence of L-cysteine will lead to the formation of a yellow to red pigment.