The lives of venerable individuals, written in Latin America during the vice-regal period, constitute a genre rich in long-standing topics and motifs. Among them, blood and fire stand out as symbols associated with red in Western culture. Wounds, the exchange of hearts, or red roses appear in the narrative with numerous meanings. It happens the same with the flames of hell. The stories are filled with highly visual scenes. This article analyzes the allegorical dimension of the red in different passages of the lives of Sister Isabel de la Encarnacion, Sister Antonia de San Jacinto and Sister María Inés de los Dolores.