Pearls come in a wide variety of colors, ranging from white all the way to black. The natural color of a pearl results from a combination of several factors:

1.Body Color The predominant basic color of the pearl.

2.Overtone The one or more colors that overlie the body color. On black pearls these colors are usually easiest to see in the lighter areas of the pearl. On white pearls they are easier to see in the darker areas.

3.Iridescence A play of lustrous colors. They may be like those of the rainbow, or they may be a subtle combination of colors such as pink, blue, green and silver. The colors of the pearls change when you move them in your hand.
www shecy com