The media invites for the launch of the iPhone 5s are out but when will the device actually retail?  

With all the brightly coloured dots across the front of the invites, the indication is that the iPhone 5S will be available in similarly bright colors.  

Reinforcing the speculation is the slogan that emblazoned the invites - "This should brighten everyone's day".  

Other highlights of the launch are set to include the announcement on the iOS7 and iTunes radio, due to launch in the US together on September 20.  

China carrier China Telecom appeared to let the cat out the bag about the release dates of the iPhone 5S and 5C with a now deleted announcement on the Weibo site indicating that the devices would be releasing early in the country.

Pre-order customers were also reportedly being offered a gift bag.  

A separate event for the Chinese press is due to take place in Beijing just hours after the US launch event on September 10, reportedly scheduled for the morning of September 11.  

Releasing early in China would signal a break with tradition as past releases have tended to focus on US and European markets first.  

The iapps.im website showed leaked photos of the rumored new iPhone 5C in what appeared to be plastic casing and devices in blue, yellow and powder pink.

According to a report by Engadget, the photos have been removed from the Chinese site following a request by a "relevant party".

The iPhone 5C is rumored to be a cheaper alternative to the iPhone 5S and iPhone 6, with a handset made out of plastic to keep the cost down.

The iPhone 5S is expected to be out in gold, black and white with fingerprint technology and dual-flash camera.

Previous releases have come around 10 days after Apple's launch events, fuelling predictions that both the iPhone 5S and iPhone 5C will be out on September 20.

This rumored date is backed up by earlier reports that a T-Mobile insider claimed employee vacations were being slashed from September 20 onwards.