This works and use a cotton swab (Qtip).Start furthest away from the colored square. Often it will draw the ink away from the colored square. If you wet the colored square the ink won't be drawn to the dampness. Do Not Rub gently work the mark. Hairspray works but can also make the ink spread. That's why I suggest a cotton swab.
Originally Posted by
Tartan
On a scrap of the white fabric, try clear hand sanitizer. If you have a bright colour backing, be careful to only get the top wet as anything to remove the mark may leave a light spot on your backing.