Soapberries are especially good for washing coloured woollens, silk and other coloured clothing. Because they are completely free of chemical brighteners and bleach, bright white clothing will eventually take on a more natural colour, however colours will keep their brightness for longer. White clothes will not have the same chemically white appearance when washed with soapberries, but you can achieve a comparable result by adding a laundry booster to your load, such as a washing soda, or lemon juice.