My understanding of South Sea pearls: Golden South Sea pearls are relatively common South Sea pearls. In terms of color, White is more precious, as they are rarer. Most Westerners prefer gold color, while Asians prefer white. Like diamonds, South Sea pearls are graded based on qualities of luster, size, color, degree of blemish-free/imperfections, and roundness. Moreover, when a strand is considered, uniformity, in terms of the the above mentioned qualities is important.
High quality South Sea pearls can be very expensive. If i can have only one strand, then I would pick white color (whitest possible with high luster), because it is more timeless and easier to match clothing. The gold color pearls are indeed tempting, though.