Theme's Show Only White Background..

[OblivionMage 0]

I have downloaded and installed (Via an FTP) two different PHP-Nuke themes. I simply unrar'd them and uploaded the files (under a folder) into my PHP-nuke's theme directory. However, when I go to the administration section and select either of the theme's, the background for all site pages turns white (for the lighter theme), or black (for the darker theme), and nothing else appears on the page. Any ideas? Like am I supposed to extract the images into the main PHP-nuke image spot instead of into my theme folder?