At the NPC Nefeeru you can recolor costumes with a Recolor Ticket (50149) .
You can get the Recolor Ticket (50149) in our cash store.
Nefeeru is located in the main office next to the positionchange NPC Seri. (main_office 60, 313).

You can see whether your costume can be recolored in the item description:

More costumes for recoloring will be added, stay tuned !
A list of all costume recolors can be found here.