To the best of my knowledge Porsche still has a Paint To Match program where, for a fee, you can have any car painted any known color. Just provide the paint code.
Yes, Porsche does have a paint color to sample program. Only $6k to get the color you want and wait until they do a batch of C2S vehicles. Usually adds three months on to the order.
That said, they do reject requests for color to sample for various reasons but if you pick a color that they have used previously they will usually approve it. They do want that $6k.
Below is a color to sample Macan in Viper green.