CGI renders of Apple's upcoming low-cost iPhone variant were posted by MacRumors, on the basis of pictures of the phone's plastic body shells being leaked to the web, a little earlier. Compared to the aluminum unibody shells of iPhone 5, the low-cost iPhone will use ABS, and will require thicker panels to achieve the same level of rigidity. So even as the screen size between the two phones is the same, the low-cost iPhone is slightly thicker (8.5 mm vs. 7.6 mm of the iPhone 5), taller, and wider.
The front bezel of the low-cost iPhone is a constant glossy white. It's the rest of the shell (sides and back) that come in various glossy color options: white, lime-green, blue, yellow, and red. Apple has several areas for cost-cutting, including display resolution and RAM. In the renders, the phone is deployed with iOS 7, which is likely. Apple is expected to launch this low-cost iPhone, along with its premium iPhone 5S, sometime in Q3-2013. That's also when iOS 7 begins to go live.