The main purposes of chlorine bleach are to return the white color to clothes and to lighten colored clothes. Colored clothes are made of threads that have specific types of molecules. The bonds that make up these molecules reflect light to display a certain color. When mixed with chlorine bleach, these cromophores or bonds are broken down, and the color therefore lightens, which is how chlorine cleans white clothes.
Chlorine bleaches are available in liquid and powder forms. The liquid form is the cheaper variety. Each fabric reacts in a different way to chlorine bleach, so check the label of the garment before using it. While chlorine bleaches can remove stains in some cases, in others it can cause them. For example, when chlorine bleach reacts with iron deposits which may be present in the water, it causes a rust-like color on the cloth. Some tough stains, such as the yellow of turmeric, may only increase if treated with chlorine bleach. In addition, the strength of the bleach used to tackle the stain can lighten the colors surrounding it.
You can use chlorine bleach to remove the color from a dyed piece of cloth; however, this is only to some extent. Those classified as reactive dyes only change color within a pre-determined range. Some other dyes do not discharge at all. There is no fixed formula to remove the color from cloth. For this, you must reach the desired mix of bleach and water through trial and error and the use of smaller pieces of cloth. One part bleach to five parts water and a constant increase in both measures helps.