Black as the Color of Priestly Devotion

Aztec priests were routinely described and depicted with skin and hair darkened by soot from the copal incense burned constantly in temple ritual, and the xicolli's characteristic black or dark coloring extended that visual language into the garment itself, marking the wearer's body as given over to a life of ascetic self-denial, regular bloodletting and constant proximity to sacred fire and smoke. Sahagun's informants describe priests as deliberately unkempt in ordinary appearance, hair matted and uncut, skin blackened, a visible contrast to the more elaborately groomed and brightly ornamented dress of Aztec nobility and warriors, reinforcing that the priesthood's status rested on discipline and religious devotion rather than on ordinary display of wealth or rank.

The xicolli's sleeveless, fringed cut left the arms and much of the torso visible, practically suited to a role that involved frequent ritual bloodletting from the arms and body, while its simple tied front closure distinguished it clearly from the more elaborate wrapped and pinned garments worn by nobles and rulers on ceremonial occasions.