Scientists have discovered a "jaw-dropping" new colour – but you can't see it

Struggling to find a unique colour that stands out for your brand or artwork? As we saw in our piece on the best uses of colour in branding, a unique colour can help a brand to stand out from the crowd. The problem is that it sometimes seems most hues have already been taken.

But in an announcement that initially had me all excited, a team of scientists claims to have discovered a new colour that's never been seen before. There's just one problem. It can only be seen if you have lasers fired into your eyes.

Just recently, I was surprised by a viral video that claimed that purple isn't a colour. Now scientists claim to have discovered a new colour. Say hello to 'olo' – or rather don't, because you can't see it.

As published in Science Advances, researchers in the US say they discovered the colour after firing laser pulses into people's eyes. That sounds like a form of torture, but apparently they wanted to stimulate cells in the retina to push their perception beyond natural limits.

After all that, olo sounds disappointingly prosaic, described as a shade of blue-green. The researchers have provided an image of a shade that say is the nearest known colour to what they saw. It's a rather shrill mint green that's quite on trend at the moment. I wonder if they haven't just been looking at the Skoda branding.

But apparently the description doesn't do olo justice. Ren Ng, an electrical engineer at the University of California, Berkeley, told BBC Radio 4's Today: “We predicted from the beginning that it would look like an unprecedented colour signal but we didn’t know what the brain would do with it. It was jaw-dropping. It’s incredibly saturated.”

“There is no way to convey that colour in an article or on a monitor,” Austin Roorda, a professor of optometry and vision science adds. “The whole point is that this is not the colour we see, it’s just not. The colour we see is a version of it, but it absolutely pales by comparison with the experience of olo.”

How did they see olo?

Our retinas have three types of colour-sensitive cells called cones, which are sensitive to long, medium and short wavelengths of light respectively. Red light mainly stimulates long cones and blue light short cones, but there's no natural light that actives medium cones alone.

That's what the researchers wanted change. They identified the exact positions of medium cones and then fired a laser to target these cones alone, "directly controlling the human eye’s photoreceptor activity via cell-by-cell light delivery."

They've called the system Oz, inspired by the Emerald City in the L Frank Baum's Wizard of Oz books. As for olo, the name comes from the binary 010, which was chosen to indicate that of long, medium and small cones, only the medium cones are activated.

So purple doesn't exist, but there's now a colour called olo that we can't actually see?

Some aren't convinced that olo can really be described as a colour, and we won't be seeing it anytime soon. Either way, the researchers believe Oz could help us learn more about colour blindness or illnesses that affect vision.

To learn more about colour, see our guides to colour theory and our guide to what is colour grading.