Created attachment 274792 [details]
Pitivi screenshot illustrating the default grey outline

Currently all the TitleSource elements have a grey outline.
It should be possible to:
- disable it;
- change its color.

+++ b/ges/ges-title-source.c
@@ -150,6 +150,9 @@ ges_title_source_create_source (GESTrackElement * object)
   background = gst_element_factory_make ("videotestsrc", "titlesrc-bg");

   text = gst_element_factory_make ("textoverlay", "titlsrc-text");
+
+  g_object_set(text, "outline-color", 0, NULL);