Brick is an all-natural building material that is made from a mix of clay and water that is then baked, or "fired," in a kiln until hardened. Different clays produce different colors, and there are many different types of clays. In addition, various natural coatings, such as sand and limestone, can also be added during the firing process to produce different colors, effects, textures and finishes. Even a brick's position in the kiln can affect the final look. When you combine these with the tonal varieties of today's mortars, you can see that your color choices in brick are virtually endless.