I used the pads continuously for one month. After about three weeks, the pads were only getting to be about 50% to 65% full. The rest of the pad was significantly cleaner. I kept on the daily pads for another week and have been on maintenance ever since. The color of my pads has always been brown/green as well. I also noticed that if I would soak my feet in Epsom Salts prior to use, the pad would pull off much more "gunk" and it would actually seep out onto the white adhesive.
I have been on maintenance for about three weeks now. The pads are still about 60% full, even after going on maintenance. The color is the same. I just sent one of my pads off to be analyzed. I can't wait to see what comes back.