Abstract
This study examined the influences of color patterns displayed on a VDT screen on work efficiency and fatigue in 16 female college students. Eight patterns with white characters were presented in the negative display mode, with 8 blue background color conditions varying in lightness and chroma levels. During a 30-minute letter search task as VDT work, no significant differences in the workload or input error rate were observed among the 8 patterns. However, the systolic blood pressure and heart rate were markedly higher after working with 2 of the 8 patterns, and the critical flicker frequency was significantly lower after working with 6 patterns. On subjective evaluation, the functional aspects of the screen, such as visibility and legibility, were more favorably evaluated when the difference in the lightness level between the characters and background was more marked. Even when complying with the character-background contrast ratio specified in the WCAG 2.0, color patterns occasionally influenced physiological and subjective fatigue. With patterns creating appropriate character-background contrast, the sense of fatigue tended to be milder when the difference in the chroma level between the characters and background was less marked.
