Seamstresses and crafters often encounter the issue of bleeding fabric. Fabric "bleeds" when the colour dyed into the fabric runs, staining the water and any other fabrics in the water. White garments, such as socks or underwear, that have been accidentally tossed into the washer with a red garment come out pink. Fortunately, It is possible to "set" the dye in a red fabric, stopping the "bleeding" issue.
Mix one part vinegar to three parts of water. Carefully immerse the fabric into the water/vinegar mixture so every bit of fabric gets wet.
Soak the fabric in the water/vinegar mixture for 20 minutes. Drain the water/vinegar mixture out of the sink and run fresh cold water into the sink. Completely rinse the water and vinegar out of the fabric.
Squeeze as much excess water out of the fabric, drape it on a drying rack in your tub and allow it to drip dry. Wet the fabric and see if the vinegar has "set" the colour. If not, repeat these steps again.
Run hot water into your sink and add the colour fixer to the water. Mix the water and colour fixer with your hand.
Immerse the fabric fully into the water. Follow the instructions on the colour fixer bottle and rinse the fabric completely.
Squeeze all water out of the fabric and allow it to drip dry on a drying rack.
Keep washed fabric separate from unwashed fabric. Be careful when treating delicate fabrics with vinegar so you don't inadvertently damage them.