Brew some hot tea, then rub the warm tea bag over the marks. It even works with sharpies!
The good old fashioned way- water and soap. :)
from the lemon juice ext.
You would need to wash your hand well with soap and water, or clean your hand with something containing a spermicide (such as nonoxynol-9) to be certain.
It depends if you're colouring you're hands with ink and it cuts them yes. But if you're just colouring you're hands no.