Have you ever seen an artist do an initial sketch using a red, purple, blue, or green pencil? How about another shade? For the most part, aspiring and professional artists alike use plain black to sketch their work before filling in with other colors.
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During the Middle Ages, color and light became important mediums for artistic expression. Color in particular was a vehicle for illustrating a higher reality, so shading was discouraged in favor of pure color. On canvas, human skin was not flesh-colored, but a pearly and ethereal white. Blood was a life-rich red, and skies and lakes were more cerulean than blue. Mixing paint became an art form in itself, as artists tried to reproduce the desired hues as clearly as possible.
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