Light refracting through prismatic crystals in a pearl's
nacre separates into spectral colors, but the separation
is more subtle than in a transparent gem.
While not affecting the quality of a pearl, color does
subjectively influence the perceived beauty of pearls.
White, silver, and cream are the most common colors
for pearls, and most will have subtle undertones.
Fancy or exotic colors are sometimes found. Examples include
gold, champagne, rose, cognac, peach.
Popularity of colors vary geographically. White is generally
preferred in the US while silver is popular in Asia. Price
premiums for particular colors is common.
But time and fashion tends to influence what is sough
after.