-The effect of blue primary color on image quality was studied. We used the KANSEI evaluation method, and for experiments, we used Semantic Differential method. First, four different blue primaries of 430, 450, 470, and 480 nm with full brightness of L max equal 60 cd/m 2 were tested.The same experiment was performed for 450, 470, and 480 nm at L max of 170 cd/m 2 . The results for the four primaries show that 450-and 470-nm blue primaries are the best. Then 430 nm was next, and 480-nm blue primary shows the worst performance. In the tests of three primaries, the 470 nm shows the highest scores for bluish test images. Results are compared with color naming data in the entire chromaticity diagram.

To investigate the best blue primary for color display from KANSEI‐evaluation point of view, evaluation experiment using Semantic Differential method was carried out using four different blue primaries of 430nm, 450nm, 470nm, and 480nm at 60cd/m2. The same experiment was done for 450nm, 470nm, and 480nm at 170cd/m2. In the results of 4 primaries, 450nm and 470nm blue primaries show the best, 430nm is the next, and 480nm blue primary shows the worst performance. In the results of 3 primaries, 470nm shows the highest scores for bluish test images. Results are compared with color naming data in the entire chromaticity diagram.