It figures that the color I finally settle on for my underdress, Rust from Fabric-Store.com, is an impossible color to match. I need a silk yarn for the fingerlooped lacing. The closest I can locate is Rainbow Gallery's Elegance Silk in Pumpkin, which is much lighter than the fabric.
I also need silk thread for the finish stitching on the underdress. I'm completely in love with the linen thread I got from Wm. Booth Draper, which I've been using on the huvet, and that I'll be using for my (hidden) constriction stitching on everything else. They have a couple different red silk threads, and it looks like the closest match, the madder red, is available in the buttonhole twist. I'm not sure that the buttonhole twist is the best choice for the other finishing, though. I would settle for using a linen for the finishing of the seams and hems, and reserving the silk for the buttonholes and eyelets, but finding a color match in linen is proving difficult as well. Londonberry's Terra Cotta comes in a 50/3 weight, which would be suitable, but once again the color isn't a close match. The next darker, Redwood, is too red. Wm Booth's madder red in the linen is a bit too red also.
Then there's Au ver a Soie's Soie Gobelin, which is the perfect weight, but no one in the domestic US seems to sell color #614, which would be a near exact match.