It's still raining and yukky so I decided to work on Jane's sweater again. After spending the morning treating it with Thiox to remove the color, all I managed to do was get it back to the original color. Which means...it must have been knitted with some of Jane's reddish-brown llama yarn and the stain was something that actually bleached the color from the llama. As you can see from the picture below, it looks just like when I got it.
So now I'm dyeing it a dark chocolate brown to see if that's going to cover it up. It looks like it may have worked (I'm waiting on the dye bath to cool so I can rinse and see what I've got). My fingers are crossed and I'll post a picture tonight or tomorrow.