What is disclosed is a novel system and method for generating a reference color difference quantity guide for spot color print applications. RCDQ values are determined for spot colors obtained from a library of spot colors. A reference color difference quantity guide is created from the spot colors and their respective RCDQ values in a manner more fully disclosed herein. Thereafter, when a user desires to render a job in a particular spot color, the associated RCDQ value for that spot color can be obtained from the reference color difference quantity guide. In various embodiments, recommendations in the form of a suggested printer to use, a media type, a halftone screen, and other meaningful assistance can be provided for selection of spot colors for a given print/copy job that are less sensitive to varying illuminations. The present RCDQ guide provides meaningful extensions in color reproduction in diverse print/copy job environments.