Azurite, cinnabar, malachite, verdigris, carbon: These are the true colors of the Bible -- the Gutenberg Bible, that is. For the first time in 600 years, the world has become privy to the mysterious substances used to illustrate the rare volumes of God's word produced by the German printer Johann Gutenberg circa 1454. It took a pair of enterprising researchers with a delicate touch to isolate the composition of the nine colors -- painstakingly concocted by unknown artists from such substances as precious metals and minerals, ground chalk, copper, plants and even insects. Gregory Smith, an artifact conservation specialist at...