The reason Apple keeps making gold-colored products? It's for the Chinese market. Tim Cook told the Chinese-version of Bloomberg Businessweek in its June 17 issue that the company does this because that's the color Chinese consumers love so much.

Also, they sell out pretty damn quickly.

China accounted for over 29% of Apple's sales in its March quarter, this year alone.

The reason why China loves gold so much is because of its affinity with luxury, and also, because of China's growing population of newly minted millionaires.