Purpureus and its chromatic universe. A methodological proposal for the study of colour terms in Latin texts · Purpureus is one of the most used colour adjectives in Latin literature due to the diversity of tones and nuances it encompasses. For this reason, it is difficult for the translator to determine the meaning of the adjective in a specific text. To solve this difficulty, we present a methodology based on the concept of colour in antiquity, from which a series of lexicographical requirements are derived (the study of the coloured entity, the intimate relationship between colour and state, the polysemic nature of colour terms) that are illuminated with the contributions of cognitive linguistics. From its application it appears that purpureus denotes one artificial and one natural colour. In the former case, purpureus applies to the cognitive domain of tissues and denotes both colour and type of tissue. Given the complex dyeing process, it is impossible to determine the hue of purpureus in a text, unless other colour adjectives appear to nuance it. On the other hand, when purpureus denotes a natural colour, it expresses colour and, in many cases, state. This is what happens when it is embodied in the domain of the human body, plants, elements of the firmament and waters where the colour also reflects health, modesty, freshness, turbulence. In the cognitive domain of gemstones, colour determines essence. Finally, when purpureus is embodied in objects characterized by whiteness like snow, it denotes the intensity and luminosity of colour.