Dark Clothing Staining Light Clothes

I use a product called "yellow out" to wash my white clothes. My whites are very bright! Follow the directions on the container to soak them overnight. My daughter has very hard water and she had white silk blouses that were very dingy. I soaked them over night and returned them to her. she thought I had bought her new shirts. This can be found in the laundry detergent isle in the "specialty" section.

Would a color catcher work? I use them all the time when I wash new fabric in batches--

You could try bleach or Rit color remover, if the stain is very large. Sometimes simply rewashing the white item will remove the stain.

don't wash white clothes with anything else but white clothes! dye will leak out of fabric, especially if washed in hot water.

you could try washing them in the washer with lots of bleach and some detergent. set it to hot water. this should lift the blue dye.