The green staining is bile which turns to brown over time. I also passed many light green stones at first then began passing tan stones. Many flushes and Gallstones later I began to pass some green stones again. I think what was happening is that I was producing some green bile which stained the stones in the gall bladder and once they came out the older tan stones from up in the bile tubules began to come out. Eventually this allowed more bile to stain the stones so some were green again. Although I have had a few Liver-Flush with no stones I'm still geting out tan and green stones 20 years later. Most of that time I had undiagnosed Celiac Disease which promotes the formation of Gallstones so as I was flushing them out I was making more.
See the CA 'Images' at the top of the page and choose Liver Flush.