[Louisiphone]

Hi everyone,
New here. I need some help identifying a chemical reaction that is causing one hand to be persistently purple.  Relevant points:
1. It started what I was using a blue scotch brite sponge dipped in water and white vinegar to clean chalk off a board. 
2. The pan is a roasting pan maybe several decades old.
3. The purple is a bright purple that only appears where my hand touched the sponge. 
4.  I can scrub it off to some degree, bu the weird part is that it will return and get more intense over the course of a day.  It will even return under my finger nails.
5. It does not stain pastic.

Questions: Is this some sort of metal compound from the pan that has gotten deeper into my skin than I would like?  Are any metal compounds bright purple?  Is this an acid sensitive dye from the blue sponge?  Any thoughts on the health effects?

Thanks.

[vmelkon]

Instead of that sponge, try something else.

What kind of pan is it? Most of them are aluminum or steel and some are copper.

[Stepan]

I have seen purple stains on (in) skin of people who work with gold solutions (gold chloride). It was due to formation of colloidal gold particles.