In this study psychophysical experiments were conducted to investigate the visual color differences of 77 textile metamers using a gray-scale rating method under five D65 simulators. The quality of each of the D65 simulators was quantified according to the method provided in CIE Publication No. 51.2 using the visible range metamerism index (MIvis). The five D65 simulators were categorized from A to D according to their MIvis values. The color difference of each metameric pair was calculated using the spectral power distribution (SPD) of CIE illuminant D65 and artificial SPDs of D65 simulators. The performance factor (PF/3) was used to indicate the agreement between visual differences under five D65 simulators as well as between instrumental color difference and visual difference. Observer accuracy and observer repeatability were also analyzed by, PF/3 measure. The experiment results showed that the visual data obtained from category A and B D65 simulators were in good agreement with the PF/3 measure and had no statistical difference in a pair comparison t test. The results also indicated that better agreement between instrumental and visual color differences was obtained using the artificial SPDs of the D65 simulator than with the SPD of CIE illuminant D65. The general color rendering index, Ra, for each D65 simulator was calculated by the CIE No. 13.3 method.