Abstract: A novel process for creating aesthetically pleasing multicolor designs and patterns in cast materials, particularly cementitious materials, which may be used to imitate natural stone in appearance. The process includes the steps of preparing multiple colors of the casting material, geometrically loading these colors in a three dimensional array in a holding container according to formulas corresponding to particular patterns to be created, placing the geometrically loaded colors into a mold by means which include pouring, extruding and spraying, consolidating the mixtures in the mold and allowing them to set, and removing the cast structure from the mold followed by polishing and sealing if required. A removable matrix in the holding container provides the ability to reliably repeat patterns according to the loading formulas.