At first I thought you meant some company thought it necessary to dye coffee because it wasn't dark enough. Then I realized you meant putting coffee in the product as a dye.

I think ultra-high roast barley would give fewer side effects than a psychoactive bladder irritant like coffee, they use it in the brewing industry to darken beers without affecting the flavor appreciably while still being about to say it only contains barley, hops, yeast and water.

At first I thought you meant some company thought it necessary to die coffee because it wasn't dark enough. Then I realized you meant putting coffee in the product as a dye.

I think ultra-high roast barley would give fewer side effects than a psychoactive bladder irritant like coffee, they use it in the brewing industry to darken beers without affecting the flavor appreciably while still being about to say it only contains barley, hops, yeast and water.