Just because Apple broke the mold by introducing new colors for the iPhone 5S and 5C doesn't mean it's keen on marketers actually featuring them in all their glory. In its newly updated marketing guidelines for the App Store, the company discourages developers from highlighting their apps on the gold iPhone 5S and iPhone 5C in green, yellow, and red:
Feature only the most current Apple products in the following finishes or colors: iPhone 5s in silver or space gray, iPhone 5c in white or blue, iPad Air in silver or space gray, and iPad mini in silver or space gray. If multiple Apple products are shown, display them in the correct relative sizes.
The guidelines apply to both Apple's official product images and custom photography. With more than 1 million apps in the App Store, policing these rules can be cumbersome. Take for example how Apple barely allowed developers to include the white iPhone in its revised guidelines last month, but that hasn't stopped them from featuring the white phone over the years.