I ahve Andreas book here in front of me (Timeless Secrets). This is what he says about stones:
"The stones come in different shades of green and may be bright-colored and shiny like gemstones. Only bile from the liver can cause the green color. Gallstones may come in all sizes, colors and shapes. The light-colored stones art the most recent. Blackish stones are the oldest. There may be dozens and, sometimes, even hundreds of stones of different sizes and colors coming out at once. Also watch for stones that are tan or white in color that may sink to the bottom with the stool. These are calcified and semi-calcified Gallstones that are released from the gallbladder and contain heavier substances with lesser amounts of cholesterol."