I had the Von Schweikert Vortex Screens for many years. Initially I had to take the sock off because the top portion of the speakers broke twice in shipping--the second after they were shipped back and reshipped. A friend of mine showed me how to fix them like new. These were the predecessor to the VR-4's back in the early 90's. The sock fitting MAY be the same on both. I had to unscrew the bottom of the speaker--it had a 2" thick MDF board that was angled in front. This allowed access to the end of the sock. The sock was held on by maybe 20 staples from a typical staple gun. Lift those out with a flat bladed screwdriver. This freed the sock to partially remove. Then gently slide the sock up the speaker until it reaches the top of the enclosure. The difference in speakers is you have 2 separate enclosures for each speaker. Mine was only one each. The top decorative board should be able to be removed, also.
I'm remembering back from a procedure I did 28 years ago, so I would definitely call Albert VS and discuss this with him. Plus, he's the only one who might be able to direct you to a proper fitting sock, hopefully in the color you're hoping for. I'm thinking there be beige or a light gray as options. Good luck.
Bob