Light and colors in the “Villa dei Misteri”

When dealing with cultural heritage, lighting design becomes really thorny, due to the necessity to keep the balance between artworks valorization and conservation requirements. Lighting characteristics have a significant impact on artworks fruition and obviously on the related chromatic perception. An aware design necessarily needs preliminary scrupulous analyses of the pieces of art to light, aiming at defining its chromatic characteristics and at understanding the way it interacts with light. Given these premises, the paper shows a methodology used to characterize artworks colors, based on on-field measurements. The method was applied to a very interesting case-study: the ancient roman wall-paintings located in the triclinium of the villa of the Mysteries in Pompeii. The study was divided in two parts: the analysis of the current lighting conditions and the chromatic analysis of wall-paintings colors. The former part reports results of illuminance, irradiance and luminance measurements, describing daylighting conditions inside the villa. The latter focuses on chromatic properties of the wall-paintings pigments. Predominant colors were identified and for each one of them an analysis area was chosen. Spectral reflectance measurements were performed for different points belonging to each chromatic area and the related CIELAB color space chromatic coordinates were calculated and compared.