Small keychain that clips to the bottom of your weapon. Has a rotating selection space for you to pick what type of chromatic damage. 1x per day, for 1 min (10 rounds). Does 1d6 damage. 

Color options include: red-fire, white-ice, black-acid, blue-lightning, green-poison

Notes: Damage: Acid, Requires attunement by a devout follower of Tiamat.