color : update error message to display quotes arround the value provided

git-svn-id: https://svn.fournier38.fr/svn/ProgSVN/trunk@3350 bf3deb0d-5f1a-0410-827f-c0cc1f45334c

color.php

@@ -254,7 +254,7 @@ class color
     $colorList = $color->colorList;
     if (! array_key_exists ($colorInText, $colorList))
       throw new \Exception (sprintf (dgettext ("domframework",
-                       "Unknown color provided to graphColor::textToRGB : %s"),
+                       "Unknown color provided to graphColor::textToRGB: '%s'"),
                        $colorInText), 500);
     return $colorList[$colorInText];
   }