Lovely Blue Dress

Lovely Blue Dress is a cloth chestpiece. It has no level requirement and is neither bind on equip nor bind on pickup, thus can be sold, traded and/or auctioned.

Source
This is one of several items that can be obtained from a Lovely Dress Box. Prior to Patch 3.3 this item was available as a quest reward from. This quest was removed in Patch 3.3, leaving the Lovely Dress Box as the only method to obtain lovely dresses.