There is an official name for the color you see when your eyes are closed: Eigengrau or Brain Gray. It translates as "gray with its own light" .
It is a bit lighter than black because the eyelid is just a thin membrane and you can still easily distinguish light and movement with your eyes closed. Although the eyelids may be closed, the pupil does not close (in fact, it opens wider when the eyes are closed) and thus information continues to be received.
Inside the eye is a protein called rhodopsin . It is a light-sensitive molecule that, when stimulated by a photon, initiates a process called visual transduction. This is the process that converts information from light into electrical information for the brain to process.
In order for the rhodopsin molecule to send its electrical message to the brain, a process called isomerization occurs. However, isomerization can occur spontaneously (that is, without any stimulus). It is the spontaneous isomerization of the rhodopsin molecule that creates Eigengrau.
Other chimeric colors
- Stygian Blue : a totally blue and incredibly black blue
- Self-luminous red: a red that is brighter than white.
- Hyperbolic orange: more orange than 100% orange
A chimeric color is an imaginary color that can be seen temporarily by staring at a strong color until some of the cone cells (photosensitive cells found in the retina of vertebrates) become fatigued, temporarily changing their sensitivity to color.
They are almost fantasy colors, like those narrated in some novels. Like Terry Pratchett in his Discworld series that began with The Color of Magic (1983), describing ‘octarine’, a color that only magicians can see.
Or Marion Zimmer Bradley in her novel The Colors of Space (1963), which mentions ‘the eighth color’ that became visible during the FTL trip. For its part, The Color of Outer Space , is a 1927 story by HP Lovecraft , and is named after an unnamed color, generally unobservable by humans, conceived by alien entities.
Because that’s how we see the world: passed through the sieve of our brain , and in turn we try to understand it through models that simplify it. Which means that the world is much more complicated than we suspect (and different):