Researchers realised a dull-looking 13,000-year-old weevil was actually covered in brilliant green, blue and yellow nanoscopic crystals.
Green is lethal: the colour of radioluminescent paint, arsenic and chlorine gas. It is also the colour of crime fiction paperbacks.
Some colour blind people only have two kinds of cone cell in their eye. Others have three kinds, but the cones do not pick up the same light waves as the cone cells in most people's eyes do.
It has long been known that colour and emotion are linked – so could colour could be used as a language to express how we feel?
As India celebrates its independence, the flag is on full display, but few people know about the complex origins of this ubiquitous national symbol.