Test the garment for colorfastness by getting an inside seam wet. Rub the area gently with a white cotton ball to see if any of the color transfers. If it does, remove the garment from the wash load to be treated.
Fill a clean bucket with 1 gallon of cool water. Add 2/3 cup of vinegar and stir thoroughly to mix.
Submerge the garment completely in the vinegar solution and allow it to soak for approximately 15 minutes before laundering it on its own. Dry the item on the highest heat allowed for the material to set the color further.
Test the dried garment again with the cotton ball. If there is still evidence of dye transfer, complete the steps again until the color is set and you can launder the item with other clothing.