Rinse the stained area immediately with cold water
Blot the area with a clean cloth to remove excess bleach
Mix a small amount of black fabric dye and apply it to the stain
Use a fabric marker or permanent marker that matches the clothing color
Try a color-restoring laundry product made for dark clothes
Re-dye the entire garment if the bleach stain is large
Use a black fabric paint for small spots
Wash the clothing separately after treatment
Air-dry the garment and check the result before repeating any treatment
Take the item to a professional dry cleaner or tailor if needed