A study of hue identification in the hue circle of the HSB color space.

The purpose of the present research was to explore the relationship between the sensory difference in hues in the hue circle of the HSB color space and their included angles in identification tasks. In the experiment, the two colors were presented separately, and the test subjects judged whether the two colors were the same or different. Five hues, called Standard Stimulus Hues and the most saturated colors in the hue circle of the HSB color space, were discussed. These are hue 0 degrees, hue 72 degrees, hue 216 degrees, and hue 288 degrees in the HSB color space. The Just Identifiable Angle refers to the included angle between a specific standard hue and the hue which cannot be identified separately and which is the furthest from the standard hue in the hue circle of the HSB color space. Analysis gave a significant main effect of standard hue. The Just Identifiable Angles for hue 72 degrees and hue 288 degrees did not differ significantly, but their Just Identifiable Angles were discernibly lower than those for the other three hues. The Just Identifiable Angle of hue 144 degrees was significantly lower than those for hue 0 degrees and hue 216 degrees. In addition, the Just Identifiable Angle for hue 0 degrees was noticeably larger than the one for hue 216 degrees, so the final outcome might show that the Just Identifiable angles of the standard hues are not equal.