diff --git a/lib/webcolor.php b/lib/webcolor.php
index aaf31d9903..f3ca6e94a8 100644
--- a/lib/webcolor.php
+++ b/lib/webcolor.php
@@ -164,7 +164,7 @@ class WebColor {
         $hexcolor .= (strlen(dechex($this->blue)) < 2 ? '0' : '') .
             dechex($this->blue);
 
-        return $hexcolor;
+        return strtoupper($hexcolor);
 
     }