For half a century the Franciscan friar Bernardino de Sahagún (1499–1590), often described as the first anthropologist of the New World, worked with his indigenous colleagues at the Collegio Imperial at Tlatelolco (now Mexico City) on an encyclopedic compendium of the beliefs, rituals, language, arts, and economy of the vanishing culture of the Aztecs. Colors Between Two Worlds examines the most richly illustrated manuscript of this great ethnographic work, the Florentine Codex, which is in the collection of the Biblioteca Medicea Laurenziana in Florence, through the issue of color.

The Codex reveals how the colors the Aztecs used in their artistic production and in everyday life, as well as the names they gave each color, illuminate their understanding of the world around them, from the weather to the curing of disease. The pigments and dyes that indigenous artists used to illustrate the Codex reflect a larger dialogue between native and European cultures, which the Florentine Codex records more fully than any surviving document from colonial New Spain.