Back on the Beta (the Build who introduced the Erebor Armor), some may remember that the Sets were Dyeable. With release this option was removed.
I talked on Bullroarer with RockX (back in HD Beta) and he told me the reason was that we will see a ceremonial version of those Sets and can dye them again.
A few pieces of Isengard Gear is available at Lalias Market but no other Pieces found their way there.

So please Release all Isengard and Erebor Sets as Ceremonial items on the Store asap!