some fixes of errors when variables were not properly set

app/controller/page.php

             $f3->set('logo', $folder->extras['logo']);
         }
         if ($folder->extras['background']
-            && !$folder->config['supressBackground']) {
+            && empty($folder->config['supressBackground'])) {
             //$background = new \Modules\CachedImage($folder->extras['background']);
             //$f3->set('backgroundImage',$background->get_src(3000));
             $background = $folder->extras['background'];

app/freaParsedown.php

         $f3 = \Base::instance();
         $data = [];
         $base = substr($href,0,strpos($href,'?') ? : strlen($href));
-        parse_str(parse_url($href,PHP_URL_QUERY),$data);
+        $query = parse_url($href,PHP_URL_QUERY);
         $fragment = parse_url($href,PHP_URL_FRAGMENT);
-        
+
+        if (null !== $query) {
+            parse_str($query,$data);
+        }
+
         if ($f3->get('LANG') != $f3->get('default_lang')) {
             if (!array_key_exists('lang',$data)) {
                 $data['lang'] = $f3->get('LANG');

app/modules/elementdispatcher.php

                     
                     $data = [];
                     $base = substr($dest,0,strpos($dest,'?') ? : strlen($dest));
-                    parse_str(parse_url($dest,PHP_URL_QUERY),$data);
+                    $query = parse_url($dest,PHP_URL_QUERY);
                     $fragment = parse_url($dest,PHP_URL_FRAGMENT);
+
+                    if (null !== $query) {
+                        parse_str($query,$data);
+                    }
                     
                     if ($f3->get('LANG') != $f3->get('default_lang')) {
                         if (!array_key_exists('lang',$data)) {

app/views/colors.css

 body {
-    background-color: {{ @backgroundColor }};
+    background-color: {{ isset(@backgroundColor) ? $backgroundColor : "#fff" }};
     <check if="{{ isset(@backgroundImage) }}">
     background-image: url(/{{ @backgroundImage }});
     </check>