This study intended to propose a guideline designed to secure safety by developing a functional color design for the color of the ordinary working clothes worn in the actual industrial settings of the machine industry in national industrial complexes in Korea. For this, a total of 6 sets of actual working clothes were produced for test, using 2-color arrangements with blue, of varying brightness and chroma for top and bottom, in relation to the visibility proven in preceding studies and evaluated in the machine industry. Blue was suggested the best proper color for machine industry by previous studies. For the material of working clothes, a total of 111 swatches were collected from the Dongdaemoon Fabric Market, and they were analyzed for color values. A total of 6 materials were used to produce working clothes for testing, which represented high brightness, medium brightness, low brightness, high chroma, medium chroma, and low chroma. Clothes were tried at the industrial settings for machine industry in a national industrial complex located in Gyeongsangnam-do and the expert satisfaction evaluation was performed based on items related with safety. As a result, higher satisfaction was shown when the brightness difference of top and bottom clothes was greater, and for chroma, relatively higher satisfaction appeared when the chroma of both top and bottom clothes was high. To secure satisfaction for both brightness and chroma, it is possible to deduce that the 2-color arrangement using the strong tone with high brightness and high chroma and the dark tone with somewhat low brightness and high chroma would be effective. Top and bottom clothes in the same color with high chroma had high visibility but had somewhat low evaluation for harmonious arrangements. This indicated that the arrangement of vivid colors for top-bottom clothes is inappropriate.