The improvement of the accessibility is important in all the people to be able to use the Internet. As the visual elements are very important factors in the Internet, in our previous study, the visibilities of young adults, the elderly and dichromatic vision persons were evaluated on white and black backgrounds using the simulation filters. Moreover, we suggested the expression for visibility prediction by the multiple regression analysis using brightness and color difference which was derived from RGB value. In this report, the integrated evaluation was performed based on the visibility prediction results of white and black backgrounds. As the results, the visibility level has been clearly classified according to brightness and color difference. For details, when brightness and color difference were the following range, it was shown that visibility of web-safe colors was judged high. If brightness (L) is L<152.7, color difference (E) is E≤65.8L-9593, if brightness is 152.7≤L≤153.0, color difference is E≤16.0L-1989 and if brightness is L≥153.0, color difference is E≤8.77L-883.1.
