According to a report, a Ukrainian retailer has already listed product pages for the iPhone 13, iPhone 13 mini, iPhone 13 Pro and iPhone 13 Pro Max. Allegedly, the listings confirm not only the colours of this year's iPhones, but also their storage configurations.
https://www.notebookcheck.net/Apple-iPhone-13-Retailer-reputed-to-have-confirmed-September-14-bound-colours-and-strange-storage-changes.560677.0.html