Impossible color

If, for example, M cones could be excited alone, this would make the brain see an imaginary color greener than any physically possible green.

The specific gamuts available to commercial display devices vary by manufacturer and model and are often defined as part of international standards – for example, the gamut of chromaticities defined by sRGB color space was developed into a standard (IEC 61966-2-1:1999 [6]) by the International Electrotechnical Commission.

[7] For example, staring at a saturated primary-color field and then looking at a white object results in an opposing shift in hue, causing an afterimage of the complementary color.

Some of the volunteers for the experiment reported that afterward, they could still imagine the new colors for a period of time.

[10] They had these observations: Some subjects (4 out of 7) described transparency phenomena – as though the opponent colors originated in two depth planes and could be seen, one through the other.

In this model, eliminating competition by, for instance, inhibiting connections between neural populations can allow mutually exclusive neurons to fire together.

However, by their own account their methods differed from Crane and Piantanida: "They stabilized the border between two colors on the retina using an eye tracker linked to deflector mirrors, whereas we relied on visual fixation."

Hsieh and Tse do not compare their methods to Billock and Tsou, and do not cite their work, even though it was published five years earlier in 2001.

[12][13][14] Introduction of a new color is often an allegory intending to deliver additional information to the reader.

[15] Such colors are primarily discussed in literary works, as they are currently impossible to visualize (when a new color is shown in the episode "Reincarnation" of the animated show Futurama, the animation for that segment of the show is purposely kept in shades of gray[16]).