I would love to know that too, writermom! I have read somewhere that the yellowy/tan ones are from the gallbladder the the green ones are from the liver...but there is a picture of a stone in the liver duct that is a yellowy/golden one...so I just don't know! Out of curiousity, did you get tan ones first and greens second? or a mixture of the two during all the flushes? (I got golden ones -and my biggest- in my first two flushes, then green ones in my 3rd) It's a good thing you're getting darker green ones now! You're getting closer then!