White clothes need to be washed separately from dark or bright colored clothes. Older clothes and things that were only lightly colored can soak up dye during a wash cycle, which can stain your whites or make them look dull and grey.
If you wash clothes that have dye or color on them, especially on a hot cycle, the dye may come out. If this happens, the dye may seep into lighter clothes and make them the same color or just a dull grey color.
Since clothes come in many different colors, it is usually best to keep light and dark clothes separate. During the washing process, the dye from darker-colored clothes can seep into lighter-colored clothes, which can damage the lighter-colored clothes. If you’re washing a brand-new dark blue shirt for the first time, it might not be a good idea to put it in with a load of whites because new clothes leak dye more than old clothes do because the dye is still fresh. Whites can be made brighter if you just wash them and add bleach or white vinegar to the wash.