I just had to come looking for your post. I remember reading it when you first posted, but didn't follow up.
I live close to the Canadian border and we get Canadian TV. I am watching a show called Steven and Chris and they are talking about your rug, I swear. They recommended a site called www.apartmenttherapy.com and it shows how to dye your rug, but it works better on natural fibers, not as well on synthetics.
Hope it helps.