what colour are gallstones
Types of gallstones. Types of gallstones that can form in the gallbladder include: 1  Cholesterol gallstones. 2  The most common type of gallstone, called a cholesterol gallstone, often appears yellow in color. 3  These gallstones are composed mainly of undissolved cholesterol, but may contain other components.t's not clear what causes gallstones to form. Doctors think gallstones may result when: 1  Your bile contains too much cholesterol. 2  Normally, your bile contains enough chemicals to dissolve the cholesterol excreted by your liver.