Change the background color, etc. for the main menu as desired.
You can register an image on this machine to use it as a theme of the main menu. Up to three files can be registered as images. To register a theme, connect the USB memory device, which contains the target theme, to this machine, then tap [Register].
[Theme 1] is specified by default.
For details on how to change the theme of the main menu, refer to Here.