THE world is full of colour – but there's more than what meets the human eye.
There is an untold number of “impossible colours” that humans can't see or even imagine.
Earlier this week, researchers at the University of California, Berkeley, and the University of Washington claimed to have discovered a new hidden colour called “Olo”.
They found a way to hijack the retina and artificially expand the natural human capacity for colour.
Using a prototype known as “Oz”, researchers flashed a laser light with a single monochromatic colour (usually observed as green) at participants eyes.
This is when participants began seeing a new colour – one they were unable to recreate when given red, green and blue light to mix.
But given enough white to desaturate it, participants and researchers discovered “Olo”, a light bluey-green colour.
There is no definitive number of “impossible” colours on Earth – but it's not zero.
And it's unclear where they might occur.
Although some animals can see them.
This is because different species have different numbers and types of colour receptors in their eyes, allowing them to see a broader or narrower range of the electromagnetic spectrum.
Themantis shrimp is king of the colour wheel here, detecting ten times more colour than a human.
It is believed to see more colours than any other animal on the planet.
There are three main categories of these mysterious shades: forbidden, chimerical, and imaginary colours.
Forbidden
Forbidden colours are those that are not possible to see directly because of the way our cone cells in the retina work.
For example, red-green or blue-yellow.
Although some people report that they can see these forbidden colours, according to Anne-Laure, founder of Ness Labs and a PhD researcher at King's College London.
You can use the templates above to see whether you are one of the lucky few.
Simply make your eyes cross so that both “+” symbols are on top of each other.
Chimerical
Chimerical colours are another type of “impossible” colour, like stygian blue, for example.
These are colours that can only be perceived through brain tricks like optical illusions or afterimages.
Imaginary
Imaginary colours are ones that cannot be physically produced or perceived by the human eye.
They exist in mathematical colour spaces but not in the ‘real world'.
