My suggestions; Take the silver trims off and paint them, cost = one can of semi gloss black. Take the silver trims off ands send them to the powder coaters, cost = more and look only slightly better.
I don't have side trims at the moment unfortunately as I bought the XPA from classifieds, and it came without trims.
It's a good idea though. I think I might have just found a silver set in a different forum so I could maybe give this a go. I'd be concerned about doing it myself... not sure I'd be happy with the finish if it wasn't Emotiva factory quality.