Jack. If you have a faded piece of the color, spray a clear coat of gloss or semi gloss urethane over it and that will pull the color out. Then compare it to the areas that have NOT been exposed to the sun. The color samples were all "printed" in a flat sheen and still are today.
Being in the business, your safer trying to match the color than trying to go with code numbers. For what it's worth.....Robert