Guess what? I had a really nice conversation with David from Green Mountain Spinnery today. He was so helpful! He had taken the time to research what would have caused the "wash out" in my sweater.
The color of Cotton Comfort Winter Beech comes entirely from an organic cotton that was bred to be that nutty brown.
However, if you wash an organic cotton that is naturally colored you can sometimes fade the color if the water is too acidic.
But you might be able to revive the color if you wash it in an alkaline solution.
I am so thankful to learn this. He is going to send me the information and I am going to experiment with my sweater. I have nothing to loose.
I am really impressed by how Green Mountain Spinnery has worked so hard to help me understand the product I purchased. Not too many yarn companies do that -- believe me, I know.
So, hats off to GMS for all their effort and I'll have to report back on what happens!