The iPhone 5S in gold is already out of stock until October. Why did this particular color of the new Apple iPhone 5S sell so fast?

The iPhone 5S in gold went on sale online just after midnight. Within 10 minutes, the ship date slipped to seven to 10 business days. By 12:30 a.m. EDT, the projected shipping dates for the gold iPhone 5S were already backlogged into October, CBS News reports.

The Apple site doesn't give a specific date for when the iPhone 5S will be back in stock - it just says October. The AT&T site promises it will ship in seven to 28 days. In Europe, shipments of all three colors were pushed into October by midday.

So why did it go out of stock so quickly?

"It's new and shiny," explained Georgia Tech student Chance Shafor, 22, who was the first in line Friday morning outside an Apple store at Lenox Square mall in suburban Atlanta, CNN reports.

Shafor said he was planning to get the gold version of the iPhone 5S, as were most of the other buyers interviewed outside the store by CNN.

"Gold is a popular choice in many markets, particularly in Asia where Apple has a stated goal of growth," said Massimiliano Pogliani, CEO of luxury phone company Vertu, in a recent e-mail to CNN. "Gold is a colour that is always in demand, whether for jewelry, watches or fashion."

Some suspect the anticipated sell out is a reason Apple did not make the iPhone 5S available for presale online, CNN notes.

"I...considered getting gold because it's the flashiest," Alex Levy, a 27-year-old law student, told CNET, CBS News reports. "But they're out of it, and the flashiness will wear off and you're stuck with a gold phone."

Gene Munster, an analyst at Piper Jaffray, predicts that Apple will sell between and 6 million iPhones around the world during the three-day launch weekend and that it will sell out of iPhone 5S devices completely, CNN reports. He said that Apple will likely move 3 million iPhone 5C models over the weekend.

The Apple store online now says the silver and space gray models will ship in seven to 10 business days in the U.S.