Is it really though? Logic would dictate that while the market for a non-neutral color might be smaller, supply would also be smaller which should cancel the demand side out.

Anecdotally, and this might be a poor example because it's an enthusiast car and not something that most people are going to be encountering, I was looking at used Porsche Boxsters earlier this year, and the more interesting colors actually commanded a premium over silver or black cars because they're much harder to find. I do wonder how that translates to something more practical, but I have a hard time believing that it would negatively impact resale value to a huge extent.