Colouring materials of pre-Columbian codices: non-invasive in situ spectroscopic analysis of the Codex Cospi

► A non-invasive study of colours was carried out on the pre-Columbian Codex Cospi. ► Cochineal, carbon black, Maya blue and orpiment were found on the reverse side. ► A large variety of organic colourants were found on the obverse side. ► Analytical data were compared with early colonial Mexican historical fonts.