VIDEO: New material reveals hidden message when you breathe on it
(WorldNews Belgium)

Our clothes, food and everyday devices get their colour from dye or pigments that absorb light. These colours fade over time, as laundry detergent ads never fail to remind us. But a different, more lasting type of colour exists as well. Structural colours Peacock tail feathers, for instance, are pigmented brown, yet they also reflect blue and green light due to their microscopic structure. These blues and greens are so-called structural colours. The wings of butterflies have structural colour as well, as do buttercup petals and some textiles. Structural colours don`t fade, but they may...