Answer:
Red-green color blindness can be broken down into two main types: Protan-type (“pro-tan”), which is a disorder of the first “prot-” type of retinal cones also called the L-cones, and Deutan-type (“do-tan”) which is a disorder of the second type of retinal cone also called the M-cones.
That is a painting of Judith and her Maidservant. 1615 painting by the Italian baroque artist Artemisia Gentileschi. It hangs in the Pitti Palace, Florence.
Copper is the correct answer.
