Some months ago, I had an online discussion about the difference between the colours purple and violet. In descriptive terms, violet is tinged with blue; purple is tinged with red. So, when the Church’s ceremonial books cite the colour "violaceus" (a Latin word), which colour is meant: violet or purple? There is no definitive answer to this, since the word itself can mean either purple or violet. See the problem? We know that the vesture of bishops is of a colour we call Roman purple. Is this the colour intended for sacred vestments in the Seasons of Lent and Advent? Some say yes, some say no. The practice throughout the world and in Rome itself has differed over the course of the last several centuries.
Let’s try to distinguish the uses of the colour "violaceus". The colour of vestments in Advent and Lent is intended to be penitential and sombre. The purple of bishops, however, is intended to be a mark of their rank, and is derived from the ancient use (by the Romans) of purple robes to denote dignity, prestige and royalty. Thus, that purple is not intended to be penitential.
Do we know what the ancient colour purple was? Until recently, no. But because of the research of English chemist John Edmonds and German artist Inge Boesken Kanold (go to website) we do now have a better idea. It is well known that the purple dye was made from the murex shellfish, which were obtained in ancient times from the seaport of Tyre. Did these shellfish produce a single, specific colour? Evidently not, because it depended on the shellfish which was used. One thing that can be said was that the dye produced by these shellfish was a rich, not a sombre colour. As to the hue? There is evidence of the shellfish producing both purple (similar to the colour of the robes of modern bishops) and also the colour of the flower violets.
In a separate article, I will try to deal with the question of when violaceus came to be designated as a pentitential colour (relatively recently) for liturgical use.
