You can add a theme to the list of available themes. The new theme must be an archive file that is tarred and zipped. That is, the new theme must be a .tar.gz file.
To install a new theme, perform the following steps:
Start the Theme
preference tool.
Click on the Install theme button. An Install New Theme dialog is displayed.
Enter the location of the theme archive file in the drop-down combination box. Alternatively, to browse for the file, click on the Browse button. When you have selected the file, click OK.
Click on the Install button to install the new theme.