Colour. It's all around us, but easy not to notice. But where do all these hues come from, and what do they represent? Katharine Allard is a pretty good person to ask - she's an ink and paint making ...

LAS VEGAS (Reuters) - German carmaker BMW has unveiled the world's first "colour-changing" car at the Consumer Electronics Show (CES) in Las Vegas. The concept car, called the BMW iX Flow ...