Not so sure the issue is color. Honestly they look pretty cool (Pun intended), however price.
Bottom line I have found especially in the last 24 months it is impossible to sell retail priced gear for more than about 30% on any used gear in general regardless of age unless its a REALLY hot item, speakers forget it! Your well above 50% of retail on these I would urge you not to put more money into them for something like the finish, your better attempting a much lower price point.
They might sell easier, but I still don't think you will see much more over 50% retail at that point even with re-finish.
Just the way it is. Even Mcintosh gear use to hold over 50% recently that has been dropping as well. Unless I am missing something I say the market is saturated, and way too many good deals out there especially on well known speakers that resell even faster. Not to say Salks are not better, but honestly when people selling 25,000 dollar Wilsons cannot even get more than about 9,000 for the pair I think you might struggle in this market even though they were never worth 25 k (an example not looking for a flame war), but Wilsons are some of the best known...
Hell I just saw some Sonus Fabers which were about 20k go for something around 5k and I have heard them which are an amazingly good speaker in the standard dynamic drive style speakers, finishes match Salk as well which I know Salk is known for.