This study was made to propose environmental conditions suitable for persons of all ages for threading a sewing needle and to examine the correlation between the visibility and color combinations of a needle, thread and background of the working environment. Visibility was assessed for various combinations of seven colors : red, yellow, green, blue, white, gray and black for the needle, thread and background. The results showed that the visibility was lowest for a same-color combination of the three items and correlated highly with color difference delta E* (ab) among the three items. In particular, lighting as well as the color difference between the thread and the background had the greatest influences on visibility. Visibility between the different age groups was then investigated. There was a significant difference in visibility between the two groups. It was assumed that since more than 70% of the adult women regularly sewed, their visibility was greater than their less experienced young counterparts．However, the results of the assessment showed a high correlation between the two subject groups, suggesting that the colors which were easily visible for the adult women were similar to those for the young women. The present results showed that the color difference between the thread and background was the most important factor for visibility in both groups, and most of the subjects indicated that it was difficult to thread a needle in a condition of less than 20 delta E*（ab）．