Pearls The color of a pearl depends on the Oysters environment. Most pearls are white, sometimes with a creamy or pinkish tinge, but may be tinted with yellow, green, blue, brown, or black. The unique luster, or orient, of pearls depends upon the reflection and refraction of light from the translucent layers and is finer in proportion as the layers are thinner and more numerous. The iridescence which some pearls display is caused by the overlapping of successive layers, which breaks up light falling on the surface. South sea pearls are the color of their host oyster's mantle and can be white, silver, pink, gold, cream, and any combination of these basic colors, including overtones of the various colors of the rainbow displayed in the pearl nacre of the oyster body itself. Additional InformationWhile the environment is a factor in a pearl's color it is a limited factor. The strongest defining factor is the type of mollusk. Different pearl mollusks produce differentcolor for different reasons.South Sea Pearls South Sea pearls are produced by the Pinctada maxima mollusk. There are two common varieties used in perliculture.