Birds-of-paradise are even colorful in the dark, with feathers and body parts that glow a brilliant yellow-green under ...

One quick fix is to use blue light filtering glasses, but researchers at the University of Houston have been working on a much neater solution: a new violet LED chip that uses much less blue light.

You can use a prism to split (or disperse) white light into a spectrum of colours: red, orange, yellow, green, blue, indigo and violet. Dispersed means that the colours are separated out.