It is said that if you use a Yixing teapot for many years, you can brew tea just by pouring boiling water into the empty pot. This is just one of the many wonderful properties of these poetic little teapots. Other colors are created by mixing these three or adding mineral pigments. A principal factor in determining the depth of the color is the concentration of iron in the clay. All the characteristic Yixing colors are called zisha, but the most celebrated of all Yixing wares is its zishayao, or purple sandware, in which a relatively high concentration of iron produces a deep purplish brown color.
Western tastes tend to run to a wider range of colors other than the prized zishayao.
How to choose Like all art, you should choose what you like. If you are a tea drinker you might want to fit the personality of the teapot to your favorite tea. You should only use one type of tea per teapot since your Yixing teapot will take on the flavor of your tea. For a bold green tea, choose a dragon teapot. A soft chamomile tea would match a flowery teapot.