Five audio-makers from around the world take over The Essay to offer a series of Radio 3's innovative Between the Ears features in miniature. Each edition takes an image as its starting point - from a radio producer who finds herself caught in a news image to a painting come to life. Chromophonia explores colour for the ears, through the eyes of two colour experts. Cheryl Porter is a books and paper conservator, specialising in medieval manuscripts and methods of creating and preserving pigments. David Batchelor is a contemporary artist and writer who works with and writes about colour. Through the colours black, yellow and blue, we hear physical processes and personal reflections. How is colour created, and how can it be used? And how does it feel to spend a career working with colour? Produced by Calum Perrin A Falling Tree production for BBC Radio 3