A polymer light‐emitting electrochemical cell (LEC) is a bipolar p‐n junction device; when biased, a dynamic light‐emitting p‐n junction is created. In this letter, we report a two color LEC in which the color can be switched by simply reversing the bias voltage. The two color LEC consists of a polymer bilayer structure sandwiched between two electrodes. In this study, the polymer bilayer consists of a poly(1,4‐phenylene vinylene) (PPV) layer and a poly[2‐methoxy‐5‐ (2′‐ethylhexyloxy)‐1,4‐phenylene vinylene] (MEH‐PPV) layer. When biased at one polarity, the voltage induced p‐n junction is completely inside the PPV layer, and the LEC emits the green light of PPV. When biased at the opposite polarity, the p‐n junction is completely inside the MEH‐PPV layer, and the LEC emits the orange light characteristic of MEH‐PPV.