New colour seen for the first time by tricking the eyes

This could be important.  I do not think that i would describe the spectrum of the INNER SUN as teal but it is certainly part of the blue spectrum.

Recall that the sky is blue because the blue spectrum is largely absorbed by the atmosphere and then re emitted as sky blue. just saying because this is not obvious.  

I wonder how all this relates to the pinal gland.

New colour seen for the first time by tricking the eyes

A device has enabled people to see a new a shade of blue-green, which they say is more intense than any experienced before

By Carissa Wong

18 April 2025

https://www.newscientist.com/article/2477068-new-colour-seen-for-the-first-time-by-tricking-the-eyes/

Our retinas could be made to see a vivid shade of blue-green

MikeCS images/Alamy

Five people have witnessed an intense green-blue colour that has never been seen by humans before, thanks to a device that might one day enable those with a type of colour blindness to experience typical vision.

We perceive colour via the retina at the back of the eye, which typically contains three types of light-detecting cone cells – called S, M and L – that absorb a range of blue, green or red light, respectively, and then send signals to the brain. When we see anything at the blue-green end of the visible spectrum, at least two types of cone cells are activated at the same time because there is some overlap in the wavelengths they detect.

Ren Ng at the University of California, Berkeley, wondered what colour people would perceive if only one type of cone was activated in this part of the spectrum. He was inspired by a device called Oz, developed by other researchers studying how the eye works, that uses a laser capable of stimulating single cone cells.

Ng and his colleagues, including the scientists who built Oz, upgraded the device so that it could deliver light to a small square patch of about 1000 cone cells in the retina. Stimulating a single cone cell doesn’t generate enough of a signal to induce colour perception, says Ng.

The researchers tested the upgraded version on five people, stimulating only the M cones in this small area of one eye, while the other was closed. The participants said they saw a blue-green colour, which the researchers have called olo, that was more intense than any they had seen before. “It’s hard to describe; it’s very brilliant,” says Ng, who has also seen olo.

To verify these results, the participants took a colour-matching test. Each viewed olo and a second colour that they could tune via a dial to any shade on the standard visible spectrum, until it matched olo as closely as possible. They all dialled until it was an intense teal colour, which supports them seeing olo as they described.

In another part of the experiment, the participants used a dial to add white light to either olo or a vivid teal until they matched even closer. All the participants diluted olo, which supports it being the more intense of the two shades.