QUMRAN, ISRAEL—Analysis of three 2,000-year-old pieces of fabric found in the Wadi Murabba'at caves, not far from where the Dead Sea Scrolls were recovered, showed that the textiles had been dyed using a pigment extracted from the murex sea snail, known to be the source of the Roman era's most prestigious colorings. One of the fabrics, a woolen piece, had an blue hue that might have been described in the Bible. Researchers at the Israel Antiquities Authority believe the color was achieved by exposing the cloth to heat or sunlight after dyeing. Prior to this discovery, only two textiles had been found with murex dyes on them.