Large-area color sensor arrays based on vertically integrated thin-film sensors were realized. The complete color information of each color pixel is detected at the same position of the sensor array without using optical filters. Sensor arrays consist of amorphous silicon thin-film color sensors integrated on top of amorphous silicon readout transistors. The spectral sensitivity of the sensors is controlled by the applied bias voltage. The operating principle of the color sensor arrays and the influence of device design on spectral sensitivity are described. Furthermore, the image quality of the sensor arrays is analyzed by measurements of the line spread function and the modulation transfer function