How to preserve denim colour... April 09 2014
Try this trick to preserve dark washes: Soak your jeans in water and 1/2 cup of white vinegar in a tub overnight. It will help set the dye in the jeans! The vinegar helps the dye adhere to the denim, so you don't end up with blue dye on white shirts, couches, etc. Just wash the jeans normally after the vinegar soak so they don't smell.