The Liturgical Arts Journal website often features historic vestments and in a recent post Shawn Tribe has a really splendid set of vestments to display. They were given in the years 1475-99 by Cardinal Giuliano della Rovere, who reigned as Pope Julius II from 1503 to 1513. The post unfortunately does not say where the vestments are but they are a wonderful survival. It would also be interesting to know if their shape is as they were originally or if they have been cut down and restyled in the Tridentine era.
In his article Shawn summarised something of the discussion about the liturgical use of blue vestments in the Middle Ages, and this set definitely accords with being used in penitential seasons. In England at that time blue or violet was interchangeable as a liturgical colour and I remember from an Alcuin Society volume that parishes followed the usage of their cathedral church. This, if I remember aright, Exeter used violet and Bath and Wells blue at this time.
The illustrated post can be seen at A Fifteenth Century Solemn Mass Set Gifted by the Future Pope Julius II
Pope Julius II
The Pope, vested here in white and gold, is depicted as Pope Gregory IX issuing the Decretals.
He is wearing the camauro under the Papal tiara.
Image: The Mad Monarchist