Terracotta is a type of ceramic made of baked but unglazed earthenware clay. Earthenware clay contains varying concentrations of iron oxide, which give them their color. By comparison, stoneware clays tend to be white or gray in color because they do not contain iron.
The natural shade of terracotta is in the brown and orange range of the color palette; however, dye is sometimes added to bring out deeper hues. For example, scientists discovered that a purple dye had been used on the Xi'an terracotta warrior statues.Learn more about Colors