Highlight the file and select Options > Apply Theme (or simply open the file). The device will reboot the interface with the new design. Creating Your Own 3 Methods of Creating Custom Themes on s40 Nokia Java
The .nth extension stands for . These files are essentially compressed packages that contain everything needed to overhaul a phone’s interface, including: Wallpapers: Static or animated backgrounds. nokia light.nth themes
System-wide colors for menus, bars, and text. Icons: Custom designs for the main menu and sub-folders. Highlight the file and select Options > Apply