Dear Chuck and Rich,
Here is another comparison, Yomud to Yomud. On top of the main carpet is a more recent chuval with a synthetic red:
When you zoom in on the knots in the chuval, you can see that the knot collar is deeply colored but the dye has bled out of the tufts, as is typical of synthetic dyes:
In contrast, the knots in the main carpet show no such degradation in color from the collar to the tuft:
In my view, the weight of evidence seems consistent with natural dyes in the main carpet.
Best regards,
David