Why the different textures and colors? Impurities are a big factor in both. Think in terms of gemstones for example. Let's say sapphires.  Sapphires come in clear, blue, yellow, pink, red, purple, green, black, brown and all shade in between. Yet they are all aluminum oxide. They can even have different crystallization patterns. Impurities that are trapped influence the color and create singular or multiple nucleation points altering the shape/texture. The same applies to the sterol-cholesterol complexes that people are passing they think are gallstones.

The Epsom salts (magnesium sulfate) used in the "liver flush" is actually a laxative, so it can promote expulsion of the sterol-cholesterol complexes that have been in the intestines a shorter time. The time spent in the intestines also affects the color and possibly the texture.

The fact that so many of these so-called stones float, especially the big ones, is proof positive that they are not real gallstones. This is further evidenced by the fact the bile ducts are INCAPABLE of expanding wide enough to allow passage of real gallstones the size of some of those people show pictures of, even if they took an entire box of magnesium sulfate. Very tiny stones or sludge may pass with the gallbladder contractions from oils in the diet, but nothing as large as people are claiming are being passed.