White models of the iPhone 4 will not be available until "later this year," Apple said in a brief statement issued Friday.

The white models "have continued to be more challenging to manufacture than we originally expected," the company said. That leaves the black iPhone as the sole model by default. Apple noted that the manufacturing issues don't affect the black version.

Apple did not explain why creating a white case is any more difficult than making a black one.

Meanwhile, bumper refunds for the iPhone 4 have kicked in online. Apple has apparently started providing refunds to the people who bought bumpers for their iPhone 4 before Apple announced its decision July 16 to give them away for free to address an antenna problem.

More: http://news.cnet.com/8301-13579_3-20011459-37.html

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