I used to own some m60 mansfields, why would you want to ruin such a nice speaker?
Maybe you should trade in for the color you want, that is if you want a nice outcome versus doing it yourself.
You might want to use the "search" tool for the word "paint" or something similar. This topic has come up before. I would also highly recommend you call Axiom to get their input. The vinyl is over MDF, which could change the way you attempt this. I believe you would want to use some very fine steel wool to lightly ruff up the vinyl. Either way I would be afraid of screwing up the speaker, there would be no going back.
Also, Fordperfect mentioned this before some time ago. Can I paint vinyl? Vinyl is a non-porous material; therefore, paint doesn’t adhere to it well. Only epoxy-based paint will stick to vinyl over an extended period of time. But epoxy paints may damage the vinyl’s surface over time."