Water quality and residue from laundry detergents and softeners can cause stains on clothes inside the washing machine. Rust-colored stains, for instance, may be caused by iron in the local water supply.
Detergent or softener residue can build up inside the washing machine when too much of either product is used on a regular basis. Stains caused by detergent and softener can be eliminated by cleaning the washer with white vinegar. After cleaning the washer, use only the recommended amount of detergent and softener, and use an HE detergent in front-loading washing machines.
Softener can also cause stains if it's added to the washer improperly. Stains caused by improperly added softener typically appear bluish and oily. To prevent stains, add softener at the beginning of the rinse cycle and after the washer has completely filled with water. White, powdery stains typically occur when laundry detergent doesn't dissolve completely. Powdery stains can be prevented by using liquid laundry soap, washing clothing in hot water or adding powdered laundry soap only after the washer has filled completely with water.
Hard-water stains are often rust colored or yellow and may leave a residue on clothing after washing. Installing a water filtration system at the main water source can help eliminate the minerals that cause hard-water stains on clothing and other household goods. Wash clothing with 1/2 cup borax per load to prevent hard-water stains in the wash.