A method for calibrating a test light to simulate a fire includes measuring a baseline resistance induced in a sensor cell of a two-color detector in response to a controlled fire. The method includes monitoring a test resistance induced in the sensor cell in response to exposure to emissions from a test light and adjusting the emissions of the test light until the test resistance of the sensor cell equals the baseline resistance of the sensor cell to achieve a calibration setting for the test light. A test light for a detector includes a housing and a first LED within the housing having a first emission wavelength. A second LED is within the housing. The second LED has a second emission wavelength. The second emission wavelength is different than the first emission wavelength.