Apple has added a new color to its range of rubber bumper cases for the iPhone 4 and 4S, releasing a scarlet bumper in support of the HIV/AIDS charity initiative Product Red. The new case is now available to purchase from the Apple Store for $29, and joins existing colors including black, white, blue, and green.

With iPhone 5 rumors reaching a fever pitch and Apple expected to unveil its latest device in mid-September, it's something of a surprise to see the company pouring resources into older models. Existing bumpers are unlikely to fit the new iPhone, which rumors suggest will have a taller frame than the the 4 and the 4S.

Still, as MacRumors points out, Apple has participated in the Product Red charity program for a number of years, and currently offers red iPod Nano models and red smart covers for the iPad. With 26 million iPhone sales in Q3 — a figure considered disappointing compared to previous quarters — there are still going to be plenty of 4 and 4S owners looking to protect their beloved devices in the months to come.