It's only a rumour, but it has happened before with Apple. It doesn't look too good and it won't probably have any new features, so the new red iPhone should only be successful if it is limited in stock,  as it will create a big demand for a low supply.

The profits are usually donated to Global Fund to fight AIDS in Africa. Previously Apple has sold red iTunes gift cards, red 8GB iPod Nanos, and red 1GB iPod Shuffles.

Source: Crunchgear, MacBlogz via IntoMobile