I've had a lot of dark brown blackish in the beginning as well. And the clay is gray. but totally could be a combination of that and the fiber I'm taking each morning... Would be much less stressful in my head if that's the case... But will stay on this track. We're doing a 90 day cleanse right now... and we're almost 3 weeks into it. We did a paragone cleanse before that (15 days on 5 days off)... then started this one...