nop 3.0 Theme Problem

I have installed nop 3.0 on a site and duplicated the Clean theme, and altered the theme.config file to rename the name. I then changed one line in the CSS file to change the navigation bar to a different color. Even though I have selected the new theme in the admin, it still tries to load the original themes styles.css file. If I delete the original Clean theme, then no CSS is applied to the site.

I presume you did not update the \Themes\{YOUR_NEW_THEME}\Views\Shared\Head.cshtml file