It would be great if webkit implemented the "background_color" member as specified in: https://www.w3.org/TR/appmanifest/#background_color-member "The manifest's background_color member describes the expected background color of the web application. It repeats what is already available in the application stylesheet but can be used by the user agent to draw the background color of a web application for which the manifest is known before the files are actually available, whether they are fetched from the network or retrieved from disk. The background_color member is only meant to improve the user experience while a web application is loading and MUST NOT be used by the user agent as the background color when the web application's stylesheet is available."