Howdy,
If in fact you have a factory one off paint your option sticker should indicate the paint code: L999. The option sticker should be on the inner right fender well behind the trunk upholstery or under the trunk hood. I also have a factory "Paint to Sample" color. However I've looked long and hard and there is no paint code number. PNA does not have it so when I repainted the front bumper I had the paint matched. Today a good paint shop can duplicate your color.
Here's a web site that will interpret your options codes if you have them. However I just open the site and the "code option" is not working so you might want to check back.
http://www.kindel.com/porsche/options.asp
See ya,