Glad to hear Tito Junior doesn't mind mounting too much either! The dark feather I'm on about is near her long wing feathers on the right. It's sticking out a little bit. It's only been visible for a few days now. I'm just surprised to see a dark feather appear as there hasn't been one there before.
She does have one dark grey wing feather on the right. It's underneath all the others. There isn't one on the other side. Some of the shorter tail feathers also have some dark blue and green colours, but otherwise her long feathers are all yellow...