Ornament kits are items that are used on certain items to change their appearance. This change is usually cosmetic and makes it untradeable.
Ornament kits gained from an elite or master tier Treasure Trail allow the player to revert their ornamented item and retain the kit.
There are also other variants of ornament kits that can be purchased from the Bounty Hunter Store. However, unlike the ornament kits obtained from Treasure Trails, players do not get the kits back if they revert the ornamented item.