"Violaceus" in the choirdress of bishops

This painting by the 18th century Dutch artist Carle Van Loo, depicts Saint Augustine of Hippo disputing with the Donatists.  The painting is also of significance in its depiction of episcopal choirdress as it was on Continent in the middle of the 18th century. This oil on canvas was painted in 1753.  Van Loo painted a small series of works depicting the life of Saint Augustine.

Something is most distinctive : the colour of the livery of the bishops is not Roman purple but a shade of blue - at least, it seems so.  This is seen in the cassocks and mozettas worn by the several bishops in the painting.  It is most likely, however, that this is meant to represent a very weak shade of violet, rather than blue itself.

We also note that the rochets worn by the bishops over their cassocks are made from linen, without any form of lace decoration.  An odd omission is the pectoral Cross, which none of the bishops seem to be wearing.

Click on the image for an enlarged view.