[tbworld]

Okay the code worked as it was. But I added a filename base so that it was easier to understand.

// Header Hook : parse_templates
    global $vbulletin;

    $nw_cssfilebase    = 'additionalcss_';
    $nw_cssbegin     = '<link rel="stylesheet" type="text/css" href="';    
    $nw_cssend         = '" ' . '/>';

    // additionalcss_00011.css  =  styleid 11        
    $nw_cssfile        = $nw_cssfilebase . str_pad($style['styleid'], 5, '0', STR_PAD_LEFT) . '.css';
    $nw_csspath     = $vbulletin->options['bburl'] . '/';
    $nw_cssout         = $nw_cssbegin . $nw_csspath . $nw_cssfile . $nw_cssend;

    $template_hook['headinclude_bottom_css'] .= $nw_cssout;
    unset($nw_csspath, $nw_cssout, $nw_cssend, $nw_cssbegin, $nw_cssfile, $nw_cssfilebase);

Create a file call it "additionalcss_00005.css" store it at your forum url.

additionalcss_00005.css

body {
 background: red !important;
}
.body_wrapper {
    background: blue !important;
}

Should turn the wallpaper to RED.


This code is a learning example it is very verbose, you do want to rewrite it for a production environment.