Limited color palettes have been employed by artists for centuries, but most have lacked a rigorous organization sufficient to permit color relationships to compete in clarity and complexity with compositional relationships. Artist James Mai proposes new, systematic methods for color selection in his modular color palettes, limited palettes whose colors conform to discrete positions within the range of color variables. These modulated colors are used to create general palette-types, each of which can yield multiple palette-versions. Modular color palettes are built from precise modulations of the intrinsic dimensions of colorhue, value, and intensityand offer new possibilities for color-motivated painting. In this paper, the author elucidates the dimensional structure of color, explains the development of his palette-types and palette-versions, and examines how modular color palettes are employed in a selection of his paintings.