By combining a series of neutral grey films with about 1,300 color samples, a color atlas illustrating over 20,000 shades has been produced, each color being specified by a simple combination of letters and numbers. This atlas was developed for use in industry, particularly paints and textiles, for communication of color requirements between customer and supplier. Although the color atlas is expensive, and even 20,000 shades still restrictive for the fine art world, it may find some use in the classification and characterization of colors on paintings and textiles in order to study long term color changes and also in the display side of museum work -- AATA