possibility of refinishing speaker

Don't do it! If you have to ask the question you don't have the expertise to do a perfect job; unless, of course, you don't care about that or about resale. My first pair of Stax f-81's had been painted in piano-black by the previous owner, and I must say that the end result, while not exactly perfect was pretty good. And DON'T USE DUCT TAPE! You'll never get the tape residue off without ruining the finish.

You could also achieve a flat black finish with a blow torch...just make sure you do it in a well ventilated room. My duct tape comment was in jest...man, you gotta be careful around here. I've thought about the opposite for my speakers...Silverline Preludes in cheesy (but OK I suppose) brown woodgrain vinyl. Part of why they're (or used to be) relatively inexpensive...anyway, I've wondered how much a woodshop would charge to put a cool striped ebony veneer on 'em...assuming I prepped the speakers. Or, I could glue orange shag carpet to the things...or print out high resolution photos of Brazilian rosewood...thinking...just thinking.

Only if you replace the surrounds with deep red ones, like the old Cerwin-Vegas, then you will have a nice looker!
I consider doing something with the dust caps too. :)

Looks like you have been given a lot of wise suggestions. One more I might contribute is go to the library and get Painting with Martha Stewart. That will help you customize your speaks. People luv customized speaks. But if you are in a hurry and you don't have much time and like the satisfaction of doing it yourself and a job well done, man, duct taping is easy! And these days they got lots of custom blacks and varios levels of dull in duct tape. Let us know how messed up we helped you make your speakers. Really or on a serious note you really should seek professional help. Refinishing for an good to outstanding result you need a skilled pro and that will cost a pretty penny.

If those side panels can be removed it would be a relatively straightforward job. It would even be easy to re-veneer them with whatever you choose. If they're not removable however, the job would be MUCH more difficult.