Taipei Railway Station, built in the late 1980s, is a station composed of high-speed railway, MRT and Taipei Railway. It has been used for nearly 30 years. From a modern point of view, it is still very fashionable, atmospheric and magnificent. Fig. 3 is the station hall, where many passengers sit on the floor. According to psychologists'observation and research, there is an interesting phenomenon, the hall floor has black and white plaid floor tiles, passengers choose Black Plaid to sit for the vast majority of people. Why? In fact, the sanitation of black and white floor tiles is the same, but the black floor makes people have the illusion of cleaner, which is in line with the saying: eyes are not seen for the net! ________