Ammonium chloride (NH₄Cl) does not produce a distinct color in a flame test. This is because the ammonium ion (NH₄⁺) does not readily emit light in the visible spectrum when heated.

The flame test relies on the excitation of electrons in metal ions, which then emit light as they return to their ground state. Since ammonium chloride does not contain a metal cation, it does not exhibit a characteristic color.