The Hindu festival of Holi has the Unexpected Elements team delving into the science of colour. First up, forget chicken and egg, we bring you a whole new controversy of which came first: colour or colour vision? Then, we learn how a new development in infrared contact lenses could extend our range of vision and help people with colour blindness.

We’re then joined by marine biologist Roger Hanlon who explains how octopuses are great at changing tones, even though they can’t appreciate the colours that they make. Plus, what’s orange, cream, 5,000 years old and worryingly resistant to most of our common antibiotics? And why does reading on dark mode leave one listener seeing things? All on this week’s Unexpected Elements.

Presenter: Marnie Chesterton, with Andrada Fiscutean and Chhavi Sachdev