An island in the Pacific has a unique genetic history that affects how its people understand color. According to legend, a devastating typhoon in 1775 caused a population bottleneck. One of the survivors, the ruler, carried a rare gene for an extreme type of color blindness. Eventually, he passed the gene to the island's later generations.

Today roughly 10 percent of the island's people are still believed to have the gene for the condition, known as complete achromatopsia, a rate significantly higher than the one-in-30,000 occurrence elsewhere in the world. But 10 percent is also high enough that the concept of color—and who can see it—has acquired new meaning among people in Pingelap.