The curtains on the latter model SMs was a blue and yellow stripe with a UV backing. Ours faded, likely from washing by a previous owner because they were slightly shrunk too. I used an outdoor fabric because I liked it and backed it with Roc-Lon blackout liner.
If you make your own replacements, I recommend you follow your own measurements and don't use the old ones as a template (because of the above mentioned shrinking). I would also checkout some of the new fabrics that are blackout built-in so no need to line.
Photo is from our cabin and yes, I like the crazy fabric, it's a bit dark back there.
Super Maramu #440
Deale, MD, USA