This volume documents Gerhard Richters 65foottall abstract stainedglass window for Germanys historic Cologne Cathedral the original of which was destroyed by bombs in World War II and thereafter replaced with clear glass. Composed of more than 11000 fourinch squares or pixels in 72 colors the window is based on Richters 1974 painting 4096 Colors a grid of monochromatic squares 64 tall and 64 wide for a total of 4096 squares which was organized and designed according to a mathematical formula