It's moot. The oysters in both locations are Pinctada margaritifera but the subtype that is used in cultivating pearls in Fiji is typica, which has an orange lip instead of a black lip. However, the typica subtype oyster is also present in French Polynesia, just in smaller numbers. So if you get a Tahitian pearl (i.e. a pearl from FP) that is the color of Fijian pearls, it probably came from a typica oyster.
In other words, it's not the location-- it's the oyster.
The difference between Fijian pearl cultivation and Tahitian pearl cultivation is that in Fiji they focus on grafting the typica subtype oyster, with a specific goal of getting those earth tone colors.