Desert Pearls of Scottsdale, Ariz., sells cultured abalone mabés grown in North American waters. While the colors are not as dramatic as the New Zealand natural and cultured mabés, current production continues to look promising, says Raymond Mason, president of DP.Orient is the iridescent spectral colors seen coming from the surface as you rotate a pearl. Overtone is usually a smaller single color, different from the body color, which appears stationary as you move the pearl, as if someone had painted it onto the surface.Pink rosés are the most popular. Colored pearls, such as goldens and blacks, gain value as the color becomes more obvious. Black pearls should have an iridescence of rainbow colors. A predominant blue or green overtone is most valued.Colors can be enhanced by dyes and irradiation. Most saltwater cultured pearls are dyed or bleached. The conchiolin layer is whitened us