A washing machine having a reminding function for preventing clothing from fading comprising an outer drum for washing water, wherein the washing machine is further provided with: - a color sensor for detecting the color of washing water to determine whether or not the clothing fades depending on color change of the washing water during a washing process, - means for issuing an alarm of clothing color fading, - a sampler arranged at a bottom of the outer drum for influent of the washing water and that communicates with the outer drum, wherein the sampler further comprises a housing defining a chamber for receiving a certain amount of washing water at regular time intervals (t) and, wherein - opposite side walls of the sampler are equipped with an LED light and the color sensor, respectively, both a portion of the housing corresponding to the LED light and a portion of the housing corresponding to the color sensor are transparent and made of a light-transmitting plate, the white detection light emitted by the LED light passes through the washing water in the sampler to the color sensor, and the color sensor obtains the color of the washing water based on a received detection light color, and - a processor is provided for comparing, at regular time intervals (t), measured color values (R n, G n, B n) detected by said color sensor with set reference values, thereby detecting the change rate (ΔR n, ΔG n, ΔB n) of the color of the washing water based on the received detection light color, characterized in that, a bowl-shaped reflective plate is provided around a periphery of the LED light which reflects a divergent white light emitted from the LED light as a parallel light to the color sensor, a convex lens is provided between the color sensor and the light-transmitting plate on a corresponding side, and the parallel detection light passing through the washing water is focused to the color sensor. - a color sensor for detecting the color of washing water to determine whether or not the clothing fades depending on color change of the washing water during a washing process, - means for issuing an alarm of clothing color fading, - a sampler arranged at a bottom of the outer drum for influent of the washing water and that communicates with the outer drum, wherein the sampler further comprises a housing defining a chamber for receiving a certain amount of washing water at regular time intervals (t) and, wherein - opposite side walls of the sampler are equipped with an LED light and the color sensor, respectively, both a portion of the housing corresponding to the LED light and a portion of the housing corresponding to the color sensor are transparent and made of a light-transmitting plate, the white detection light emitted by the LED light passes through the washing water in the sampler to the color sensor, and the color sensor obtains the color of the washing water based on a received detection light color, and - a processor is provided for comparing, at regular time intervals (t), measured color values (R n, G n, B n) detected by said color sensor with set reference values, thereby detecting the change rate (ΔR n, ΔG n, ΔB n) of the color of the washing water based on the received detection light color, characterized in that, a bowl-shaped reflective plate is provided around a periphery of the LED light which reflects a divergent white light emitted from the LED light as a parallel light to the color sensor, a convex lens is provided between the color sensor and the light-transmitting plate on a corresponding side, and the parallel detection light passing through the washing water is focused to the color sensor.