The first objective was achieved through three documentation missions to the Bardo museum and the Dougga site. The documentation produced has been interpreted to understand the chromatic visual aspect and the techniques used to create it. The project enabled the construction of the first dataset of polychrome Roman sculptures (115 items) in proconsular Africa, and more generally the largest corpus of Roman polychrome sculptures belonging to a single territory. The second objective was achieved through the study of the photographic and documentary archives of the excavations from which the statues originated, to understand their original visual context, and the study of comparative written and visual sources, to understand the meaning of the colours used.
The main scientific results could then be linked to the understanding of technical and cultural phenomena.
The technical practices have been documented in terms of the palette (earths, minium, sandyx, cinnabar, mimetite, Egyptian blue, organic purple and pink, bone black, lead white, leaf gilding), the rendering of shadows (super-imposing a darker tonality or adding lead or black and blue), the application technique (on a preparatory layer with calcite or gypsum, or directly onto the marble), the binder (Punic wax, casein, egg, "a fresco"). Moreover, in 10 sculptures a restoration of the colour was documented, showing the transition from a realistic use of colour to a more contrasted and less nuanced use.
The colours' appearance aimed to create an illusionistic effect: on the one hand a search to render the human nature of the characters, on the other the desire to imitate precious or meaningful materials. A series of statues, not produced by African workshops, have white skin highlighted in yellow or brownish red, orange lips, eyes marked in blue or black, and blond, brown or chestnut hair. The majority of the other statues analysed are characterized by a polychromy in tones of yellow, orange and red with traces of gilding. A third type consists of statues in which only certain details are coloured, and these contrast with the white of the apparent marble. A fourth type consists on the use of painting to give a prevalent colour peculiar to a deity: for instance, red for Jupiter, brown-black for Isis and Serapis…Cross-referencing the collected visual and written sources and the virtually reconstructed coloured statues, we can begin to understand the cultural value of colour. The colour probably marks the positions of human beings and the gods within society and makes their sphere of influence perceptible to the viewer: in the first type, probably by giving an idea of a physical and living presence; for the second, by imitating gilded bronze or ivory and metal statues, associated with heroic or divine characterisation; for the third, an intermediary status; for the fourth, by hinting at their sphere of influence.
