This stain is difficult to remove because the color is deep and persistent.
On Washable Fabrics
Rinse stains in tepid water. Rub in a glycerin solution, leave for half an hour, and rinse. Launder in enzymatic detergent, if suitable. Use a hydrogen peroxide solution on persistent stains.
On Other Surfaces
Do not attempt to remove stains on nonwashable fabrics or furniture yourself. Have both slipcovers and upholstery professionally cleaned.