19-20 years ago, I got hired as an inspector by a carpet retailer to check out a color change problem his client was having with her new carpets. A 2 year old Beige color nylon carpet in living and dining room, 490 sq ft, getting greenish hue spots even under the furniture. I found about 35-40 greenish spots none larger than 3 inches in diameter in these 2 areas. It was my first run in with what we all know today as "Simple Green" in the early days it was sold through auto parts stores and the husband restored old cars.