Korean researchers have managed to produce coloring by applying magnetic field to a nanoparticle suspension.

The way it works is unlike pigments commonly used in printing, cosmetics and a number of different applications. Instead, Sunghoon Kwon's team at Seoul National University, South Korea, created nanostructures similar to those giving iridescent coloring to butterfly wings. Melanin rods are aligned in a pattern, which interferes with white light altering the color.

Researchers used a similar solution – particles 100 to 200 nanometers across suspended in a resin. When a magnetic field is applied to the material, the particles align themselves in chains along with magnetic field lines, reports New Scientist.