My pads were always greenish-gray. Never terribly dark.
I had trouble with the white spots too.
I was wondering, if it just did not stay close enough to the skin.
It helped when I put extra tape around it. I also started using it in daytime so my shoes kept the good contact.
I found it helped.
I also look through the pad to make sure the powder is spread out. When you put in on you have to be careful so the powder does not shift.
It seems even with a stone free liver, you can still have toxins in your body, based on Paulette's experience.