The analysis of color image sequence is very heavy if the analysis is carried out for each image. But, in many practical cases, there is no need to know the precise motion and shape. In other words, the rough estimation of motion and shape is sometimes practically enough to understand image sequence. To achieve this rough estimation of motion and shape speedily, a method using color multiplex image is proposed in this paper. The color multiplex image is defined as a time averaged image of a given image sequence. In this paper, principle and eflectiveness of the proposed method are discussed. For example, it is shown that if the moving object is square, the size and the velocity of the moving object can be estimated by the analysis of color multiplex image.