This product is one of those things I've been using for years, on a regular basis, but have somehow never posted about: Schwarzkopf's Igora Color Remover is a light fluid which lifts colour stains from the skin, without drying the skin out. I used to use it to tidy up my hairline after applying at home permanent dye, and I now use it to tidy up my hairline (and my wrists, fingers, etc) after applying highly staining vegetable colour to perk my red hair up in between permanent applications. Before I picked it up for the first time on the offchance from eBay, I would scrub at my skin with water and exfoliator to try to shift colour stains - now I just use a little squirt of this on a cotton pad.
You'll find it on eBay, and from Salons Direct, where it'll cost around £4. Bargain, really!