Dye on Skin
Rub Vaseline all around your head at the hairline before using semi-permanent dye on your hair to prevent skin staining. If you do get stains during the dying processes, rub the Vaseline into your skin in a circular motion. Then wipe it with a damp towel to remove the dye.
Use a bit of dampened ash to scrub dyed areas of skin and lift the stain. After the semi-permanent dye rubs off, wash the ash away with soap and water. You can use cigarette ash or fireplace ash, but creating your own ash from non-toxic materials is the safest bet.
Scrubbing dyed skin with a toothbrush and whitening toothpaste is another method of removing dye stains. You can also try dipping a cloth in milk and scrubbing the skin. Hydrogen peroxide or diluted nail polish remover on a cotton swab also works well. You can even use equal parts of baking soda and dishwashing liquid. Never use abrasive household cleaners to remove skin stains! And keep any cleansing agent mentioned here out of your eyes.