Exactly my point. These are used merely to change the color of a fire that will last for a few minutes.
Also, these items will be available in TT rewards for a long time, if not forever. If however, you ever see them disappear from the list, be sure to buy up a few, as they will eventually be worth something.
At the moment like 10k street price in world 2 but nothing that big. I would just keep until maybe they are taken out of the treasure trail rewards. Then you could make some big bucks.