In the last three decades many LED-based colorimeters have been described in the literature [3]. In the proposed colorimeters the detectors (photodiodes or phototransistors) have usually been connected to operational amplifiers for amplifying the out put current. In most cases, either the optical fiber bundles are employed to guide light radiation of LED to the measuring cell [4] or the instruments controlled by a microcomputer [5] or software and complicated circuits employed to acquiring and processing data [6]. A few of these are relatively simple and devised for educational purposes [7,8]. Although the reports in the literature reveals a great deal of advances on colorimeters, still efforts for simplifying the colorimeters seems to be of importance.