White and grey items have been made transmoggable in Patch 10.0.5, and many items are now cosmetic – usable by any character regardless of armor type. This includes several gorgeous hanboks and danguis, some of which are just a little more special than others!
The White Traditional Hanbok, Dark Green Wedding Hanbok, and Royal Dangui are the easiest to obtain. Purchase them at any time from Lisbeth Schneider in Stormwind City, Sheldon Von Croy in Undercity, or Geenia Sunshadow from Moonglade.