There have been a number of taste tests that show that, when blindfolded, most people can't distinguish between Coke and Sprite, let alone Coke and a close imitation, without the visual cue: throw together enough sugar, acid, and carbonation, and it overwhelms the body's ability to distinguish taste. It's a story often repeated in marketing (like Twitchells' Branded Nation), because forging a distinction between indistinguishable parity products is marketing's job.
https://www.washingtonpost.com/archive/lifestyle/food/1982/0...