• Translation is often described with opposed terms like loyalty and betrayal, even though the work of translation defies such a description. New research in translation studies argues for the value of mistranslation and untranslatables, especially in recovering Indigenous knowledge production. This study joins these efforts by documenting how technical writers in the colonial Andes used Quechua terms to form a patois called “Quechuañol” (Quechua plus español) and how this hybrid Andean language was obscured in translations of scientific texts in early modern England, Germany, and France. As translators reinterpreted metallic classifications in Quechuañol, including “Pacos, Mulatos y Negrillos” (“paco, mulato, and negrillo metals”), they chose terms that communicated their own, culturally specific ideas about color and categories. Tracing mistranslations in the Atlantic world allows us to document both the Indigenous intellectual contributions to the technical arts and the development of early modern racial classifications.