I once tried shrinking a zombie Mego head and had reused acetone that I had shrunk something red in and the acetone had a watered down kool-aid look to it. I didn't care since I intended to mold and cast the zombie Mego head, but I was surprised to find that the residual red dye had stained the vinyl and cured the zombie problem. The head is now a nice flesh color and has yet to fade and I did this over 10 years ago.
Sorry, I don't have any suggestions, just another cautionary tale.
Expectation is the death of discovery.