By far, it’s the Peacock overtone. Peacock has quite a range, but can most often be described as a mix of Teal Green, Gold and Rose swirling over a dark, charcoal grey body color. The pictures below are good representations of the classic Peacock overtone. Notice some of the pearls have more intense Rose coloration than others, but the main ingredient colors are all there in varying degrees.
Other popular overtones include Silver, Blue-Green and Rose, as seen below.
Tahitian pearls are also known for their rare overtones known as “exotics”. Pistachio, Emerald-Green, natural Chocolate, Cherry and Sky Blue are just a few of these intense, gorgeous colors. See the images below to get a good idea of the color ranges these overtones represent.