Pollia berries also known as marble berries are small, very hard seeds from an African plant known as pollia condensata. Unlike normal plants, which expresses their colour due to the presence of pigments which absorbs lights in them, the pollia berries doesn't have any pigment but they express the most brilliant of biological colours ever seen.

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This has attracted the attention of researchers as they thought of extracting the pigments in the berries for analysis but came to realize that the pollia berries have no pigment. If they don't have pigments, then how come they express such bright blue colours?

The pollia condensata is able to achieve this by a well structured surface that is able to interfere with visible light a process referred to as structural colouration. When researchers examined the tissues of this berries, they observed that the bright blue colour is from the molecular level. The cell wall of the berries were made of well arranged threads that are arranged to form a spiral or helical structure. The arrangement of this threads helps in the scattering of visible light which gives the bright colour.

Since the brilliant blue colouration is made from the structure and not from pigmentation, the pollia berries can retain their bright colours even after decades of been plucked from the plants.

The method of colouration of the pollia berries has made researchers conclude that imitating this method of colouration in the field of science will help in the production of fade resistant dyes.

Reference

This African Fruit Produces the World’s Most Intense Natural Color

Pollia condensata