(Note: This list was made in MoP during patch 5.4. If you're reading this later than patch 5.4, I cannot guarantee these items will still be available.)
The quest The Coldbringer that you pick up from Koristrasza at the beginning of the instance offers a few unique colored pieces of gear as a reward.
Belt of Tyrannic Rule - This plate belt doesn't have a unique model or color, but it you're looking to try to complete the Redpath Plate set, it can take the place of the Rockpool Belt if you did the quest already.
Chestguard of Redemption - This is a mail chest that doesn't have a unique model, but it has a unique color. It is brown and yellow and part of the Thousand Needles Mail recolor set.
Coldbringer's Leggings - These cloth leggings aren't a unique model, but they have a unique color. They are the only cloth leggings of this model to have a blue band around the top with the purple design on the sides.
Mordresh Fire Eye
Deathmage Sash - This is a unique model and color cloth belt. It is black and dark purple and matches the Twilight Trappings perfectly.
Fleshhide Shoulders - These orange and tan leather shoulders are not a unique model, but have a unique skin. If you look closely they resembles sewn together flesh, like the Gnoll tents.
Amnennar the Coldbringer
Bonefingers - These are a unique model and color leather gloves. Their look reminds me of the no longer available Deathbone Gauntlets.
Deathchill Armor - This mail chestpiece isn't a unique model, but it has a unique color. It is the only grey version of this chestpiece available.
This NPC is located in a cage in the Murder Pens right before you get to Mordresh Fire Eye. After freeing and talking to him, he should give you the option to learn Major Troll's Blood Elixir for Alchemists (180+) and Goldthorn Tea for cooking (175+).
Boar Champion's Belt - This mail belt isn't a unique model or color. It shares the same red look with the Demon-Forged set and is a good alternative in case you did the quests for the others or can't get them to drop.
X'caliboar - This two handed sword isn't a unique model, but it has a unique hilt color. This version of this sword is the only one to have a solid brown hilt.
I may have made some mistakes, so if you find an error please feel free to leave a comment below! I feel if you start farming now, you probably will have more than enough time to get all the items you want! This doesn't mean some of the item models won't be reused, but it's better to grab something now than regret it later! Good luck and happy farming!