Have you ever thought what it would be like, to live in a world without colour? Free yourself for a moment from your experience, forget all that you've learned and start using your imagination. Try to visualize your body, the people around you, the seas, the sky, trees, flowers, in short, everything in black. Imagine that there is no colour around you. Try to think how you would feel if people, cats, dogs, birds, butterflies, and fruits had no colour at all. You would never want to live in such a world, would you?