The stain may have gone down into the vinyl. You could try dilute bleach, but otherwise I doubt much can be done except to paint it with a special vinyl dye or paint, for example the type sold for automotive upholstery, which seeps down into the surface of the vinyl so it won't chip off. I'd try it in an inconspicuous area first.
I used to use that in silver or black color, to color match CDRW/DVDRW drive bezels to cases. All the drives were nearly free after rebate (why I had a stockpile of so many of them instead of buying different bezel color drives in later years) and almost all started out with white bezels.