I had my car repainted a couple months back, and spent literally years agonizing over the color.
My car is a GT5-S, and was painted Pearl White by the factory. When I bought the car, I was originally planning on painting it because I wasn't thrilled with white, but it eventually grew on me, and I really liked the original color. It had shades of purple and pink - like a pearl (duh!) when the sun hit it from certain angles.
I spoke to the Factory numerous times, as well as Carrozzeria Campana, who apparently painted the late-model Panteras. Nobody was able to give me a paint code.
I eventually went to a shop that had a magic machine that is supposed to be able to duplicate any paint... Even so, they made 30 samples for me, with more or less pearl effect, until we came up with a recipe that was more or less identical to the original.
Even so, it is close but not identical, but I'm happy.
I'd recommend going to a paint distributor - PPG, Sikkens, etc - and looking through their catalogs. They have a HUGE catalog of existing colors. You would have to have after a really special color if you can't find something you like in the catalogs.
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