I tried rubbing alcohol first before the acetone and it didn't seem to work. Nail polish (with acetone) worked well and removed all of the stain!
The original white finish on the cable is still there, so it doesn't seem like the acetone did any more damage than the stain itself.
Just a heads up, it was the black cloth that came with the computer that bled onto the cable. I should have known better than to use a black cloth on a white cable, but if anyone is wanting to clean their Mac with the cloth consider using a different one
Thanks for the help, the cable looks new again.