I do have an image of a Cologne style dress with an apron made from a purpley fabric that is the same colour as her undersleeves... It's a brocade. The image appears to be from Sotheby's.
Oh my, what a fluke.. it was the first bookmark I clicked;)
http://search.sothebys.com/jsps/live/lot/LotDetail.jsp?lot_id=43K2S


I read the woodcuts as being brocades if the pattern is less random than the wiggles for watered silk...

In Davenport's book:
"Both aprons and skirts are embroidered or made of brocade or velvat to match the bodice, as well as made of linen."