The document discusses 6 coins from different years and the metals they are made of. It notes that the color of the coin is important and then provides the color and metal for each coin, including: a 20 francs 1819 coin that is yellow gold; a 10 centimes 1941 coin that is grey zinc; a 5 centimes 1914 coin that is red copper; a 2 francs 1919 coin that is grey silver; a 5 centimes 1962 coin that is grey iron; and a 2 francs 1943 coin that is grey aluminium. It concludes that gold is yellow, copper is red, and the other metals are grey.