colorant

It joins galdieria extract blue, a blue colorant made from a unicellular species of red algae called Galdieria sulphuraria; calcium phosphate, a white powder; and butterfly pea flower extract, a blue color that can be used to create various shades of blues, purples and greens.

Butterfly pea flower extract is derived from a clitoria ternatea plant, often used as a natural food colorant, according to the NIH.

The latest initiative comes more than three decades after the colorant was barred from cosmetics and non-oral medications due to potentially causing cancer.

The ultra-thin colorant is around two microns thick, and although less reflective, it's visibly blue and reflects UV well, possibly paving the way for new colorant methods.

"It shows that nature has evolved to use a really neat trick, an ultrathin layer for an important colorant," added Rox.