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7619


Date: April 20, 2025 at 16:12:19
From: Skywise, [DNS_Address]
Subject: Scientists claim to have discovered 'new colour' no one has seen befor

URL: Scientists claim to have discovered 'new colour' no one has seen before


Direct link to research paper:

https://www.science.org/doi/10.1126/sciadv.adu1052

From BBC:

A team of scientists claim to have discovered a new colour that no human
has ever seen before.

The research follows an experiment in which researchers in the US had laser
pulses fired into their eyes.

By stimulating specific cells in the retina, the participants claim to have
witnessed a blue-green colour that scientists have called "olo", but some
experts have said the existence of a new colour is "open to argument".

The findings, published in the journal Science Advances on Friday, have
been described by the study's co-author, Prof Ren Ng from the University of
California, as "remarkable".

He and his colleagues believe that the results could potentially further
research into colour blindness.

Prof Ng, who was one of five people to take part in the experiment, told
BBC Radio 4's Today programme on Saturday that olo was "more saturated than
any colour that you can see in the real world".

"Let's say you go around your whole life and you see only pink, baby pink,
a pastel pink," he said.

"And then one day you go to the office and someone's wearing a shirt, and
it's the most intense baby pink you've ever seen, and they say it's a new
colour and we call it red."

During the team's experiment, researchers shone a laser beam into the pupil
of one eye of each participant.

There were five participants in the study - four male and one female - who
all had normal colour vision. Three of the participants - including Prof Ng
- were co-authors of the research paper.

According to the research paper, the participants looked into a device
called Oz which consists of mirrors, lasers and optical devices. The
equipment was designed previously by some of the involved researchers - a
team of scientists from UC Berkeley and the University of Washington, and
updated for use in this study.

The retina is a light-sensitive layer of tissue at the back of the eye
responsible for receiving and processing visual information. It converts
light into electrical signals, which are then transmitted to the brain via
the optic nerve, enabling us to see.

The retina includes cone cells, which are cells responsible for perceiving
colour.

There are three types of cone cells in the eye - S, L and M - and each one
is sensitive to different wavelengths of blue, red and green respectively.

According to the research paper, in normal vision, "any light that
stimulates an M cone cell must also stimulate its neighbouring L and/or S
cones", because its function overlaps with them.

However, in the study, the laser only stimulated M cones, "which in
principle would send a colour signal to the brain that never occurs in
natural vision", the paper said.

This means the colour olo could not be seen by a person's naked eye in the
real world without the help of specific stimulation.

To verify the colour observed during the experiment, each participant
adjusted a controllable colour dial until it matched olo.

Some experts, however, say the new perceived colour is a "matter of
interpretation".

Prof John Barbur, a vision scientist at City St George's, University of
London, who was not involved in the study, said that while the research is
a "technological feat" in stimulating selective cone cells, the discovery
of a new colour is "open to argument".

He explained that if, for example, the red cone cells (L) were stimulated
in large numbers, people would "perceive a deep red", but the perceived
brightness may change depending on changes to red cone sensitivity, which
is not unlike what happened in this study.

But the study's co-author Prof Ng admitted that although olo is "certainly
very technically difficult" to see, the team is studying the findings to
see what it could potentially mean for colour blind people, who find it
difficult to distinguish between certain colours.


Responses:
[7620] [7621]


7620


Date: April 20, 2025 at 23:17:26
From: ryan, [DNS_Address]
Subject: Re: Scientists claim to have discovered 'new colour' no one has seen...


kind of interesting...but it's like telling me they found a sound i cannot hear...whose numbers are increasing rapidly...lol...


Responses:
[7621]


7621


Date: April 21, 2025 at 08:07:52
From: Skywise, [DNS_Address]
Subject: Re: Scientists claim to have discovered 'new colour' no one has...


Many years ago I went down the rabbit hole of color vision. I learned a lot.

As you may know we have three color receptor cones. Most people call them
red, green, and blue, but the reality is different. Instead they are called
long, medium, and short, for the wavelengths they cover. The response curves
of the cones overlap, especially the long and medium cones as you can see in
the chart.



Basically, it is impossible to see a color and stimulate only one cone, except
at the extreme violet and red ends of the spectrum.

What the scientists did was find a way to stimulate only the medium cones while
avoiding the long and short cones. This resulted in a neural stimulus that can
not occur naturally and thus our brains perceive something it has never perceived
before.

Related to this is something known as an impossible color. Examples are
yellowish-blue, or greenish-red.

Wikipedia article on Impossible Color

It's possible to sometimes perceive this contradiction of color by having each
eye see one of the opposing colors by crossing eyes. I can do it OK for the
greenish-red but struggle on the yellowish-blue.

Color perception is fascinating to me. A topic opener I sometimes use is to
point out that there is no such thing as color. It's all in our head.

Brian







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