Around 90 samples of Roman wall painting dating from the first to the third century AD were analysed using different analytical techniques: X‐ray diffraction, X‐ray fluorescence, infrared spectrometry, scanning electron microscopy, energy dispersive spectrometry, optical microscopy and physico‐chemical tests. The identified pigments are: ash, calcite, carbon black, celadonite, cinnabar, Egyptian Blue, glauconite, goethite, hematite and red lead. Pigment mixtures were used to get other colours such as brown, pink or purple. Three types of plaster were used: a first, and most dominant, with river sand, a second with crushed tile for damp places and a third, to which cinnabar was exclusively applied, was prepared with crushed calcite cry