Pigments have been discovered on Roman stone in Scotland | Photo: Hunterian Museum, Glasgow University
Using Raman spectroscopy and X-ray fluorescence, in 2018 scientists discovered traces of red and yellow pigments on distance-measuring stones that are part of the fortifications of the Antonin Wall in Britain.
These stones were decorated and the colours were supposed to raise the meaning of the message and influence the local population. And so red was used to paint coats or blood of captured barbarians. The skin was coloured with ocher.
Probably not all local residents knew Latin on the inscriptions, yet they certainly understood the message from the reliefs.