BCX size 5 cocktail dress

Beautiful gold sleeveless size 5 Juniors cocktail style dress. It has a bow on one shoulder while the other side is strapless. It has a zipper on the back, while the front actually has 2 small pockets! A dress with pockets 😃😃 New with tags This is NWT. BUT... I did find a small discoloration on the back (please see photo) it is a spot with a reddish hue. I bought it that way, so I am not sure what it is or what happened. At first glance I didn't even notice it.