Designer Dispatch has the Wired Satin Tubing. You can usually always get white, black and silver. My preference has always been the ivory. They have had a problem with the wire stiffness with the ivory that they have been working on. I don't think that it has been corrected yet-I may be wrong tho. I was lucky to be able to purchase a bunch of colors when they were on clearance from one of our suppliers. So when we are making our bows, we try to match the wristlet color to the bow. We have red, teal, gold, ivory, wine, pink and blue. Wish they would bring them back.
We also tried using another product called Bedford Bendable Ribbon that Ardith Beveridge showed at one program we were at. You can do several loops for the bow, then use a couple for the wristlet on the back. It is a shiny plastic covered metal. It works, but not as comfortable. It does come in a bunch of colors. I don't know where you would purchase this product from.