Anonymous said use the same colour to take it off, which is really good advice, but, it only works before you wash off the colour, the best way to take it off if you have already taken off the colour is, ( it's sounds gross ) get some cotton wool, damp it, dip it in some ash from an ashtray, ( if your a smoker, great, if not go see a neighbour ) and rub it gently on the stained skin and it will remove the stain, ( the darker the colour, the harder it will be no matter what you use ).

skin oil or really oily face cream works very well

Rubbing alcohol. Put it on a cotton pad or q-tip.

the best thing to do is wipe it off with a wash cloth as you go anything that gets onto face. However if you do get a stained face someone told me to try using the same color while your in the shower and rub in circular motion it should come off then shampoo skin off not hair. Also I have used rubbing alcohol in the past and have heard toothpaste works too. Also baking soda mixed with dishwashing liquid have heard that works well also. Good luck.