Like Blueduck said...it may take 3-5 shakes before you start passing noticeable mucoid plaque. The darker color...if not a result of something in your diet like spinach...may be some of the old gunk mixing in with the newer waste material. I've never seen a guide for what the different colors mean, but I've always associated greenish waste with lots of toxins...I often feel worse just before passing it and better after I do. It might indicate that lots of stuff is being dumped by your liver with the improvements in your digestion. It definitely sounds like you're benefitting from the p&b...a very good thing!