Locating the Unique Hues

Unique Hues

One can see so many different colors in the environment. And yet there are only four colors that occupy a special place in color perception. They are called unique hues and they originate from the opponent colors theory proposed by Ewald Hering in 1878 [1, 2]. The theory postulates three opponent processes: two chromatic processes of red-green and blue-yellow and one achromatic process of white...

Neural basis for unique hues

p = 0.38, respectively). Moreover, analyses of only high confidence states yielded similar results as when highand lowconfidence states were pooled (see Supplemental Data). Together with the numerically large and robust difference between expected and unexpected percepts in the test phase, these observations speak to a true perceptual bias rather than a mere response bias. Our work shows that e...

Empirical evidence for unique hues?

Red, green, blue, yellow, and white have been distinguished from other hues as unique. We present results from two experiments that undermine existing behavioral evidence to separate the unique hues from other colors. In Experiment 1 we used hue scaling, which has often been used to support the existence of unique hues, but has never been attempted with a set of non-unique primaries. Subjects w...

On the Nature of Unique Hues

A neural signature of the unique hues

Since at least the 17th century there has been the idea that there are four simple and perceptually pure "unique" hues: red, yellow, green, and blue, and that all other hues are perceived as mixtures of these four hues. However, sustained scientific investigation has not yet provided solid evidence for a neural representation that separates the unique hues from other colors. We measured event-r...