Colours: from Cave Paint to Nanotube Black

There's a theory that the invention of paint had something to do with the dawn of humanity. We are on a never-ending quest to create brighter, better colours. From grinding rocks, to crushing bugs, concocting chemicals and now manipulating nanotubes - a mind-boggling array of beautiful pigments and dyes litter our history.

Today's guest is Kassia St Clair, author of international bestseller The Secret Lives of Colours.

Produced by Freddy Chick, Senior Producer is Charlotte Long