Wash the garment alone several times with or without detergent to rinse out excess dye.
Warm or hot water are more effective at removing dye.
Place the wet garment against a piece of scrap white fabric and iron it dry. If dye has transferred onto the white fabric, there is still excess dye and you should return the garment to the washer.
Add a small amount of professional dye fixative into the beginning of a wash load containing only the dyed item.
Wash out excess fixative. Run the garment through a cold water cycle after using the fixative.