We had one stiing next to a deep blue in our showroom. At 10 feet it looked the same. Its subtle and IMO not worth an extra 500 but it will be uncommon. We sold one car with it in 2015.

 

It could add a few more visual horsepower? Won't know till you drive it.

 

Although it is 2021 and years since your posting, wanted to add my two cents about red. Yes, red definitely required the addition of gold historically to achieve the color. Which is why royalty wear red, we have the "red carpet" and so on. To this day if you have red glass for stained glass work it has gold in it to achieve the color in the best grades of glass. (And the color is simply stunning, but the stained glass will cost a mint.)
In automotive paint other ingredients have been found to achieve the color: "Common red pigments include the minerals iron oxide, cadmium, and cuprous oxide and various synthetic organic pigments."
Color history is fascinating so if you are into history strongly recommend you check out more articles/videos, etc as to how the "ancients" made their paint. Been a bit of change since the cave walls, I have to say!