“blue coloration by intermolecular co-pigmentation alone is not common, and when it occurs, it is usually the result of co-pigmentation of anthocyanins with glycosylated flavonols and flavones”

Blue was the last color to be spread in Nature by the anthocyanins present in angiosperms, and the last color to be managed by Humans in Anthropocene. Blue also appears in a small number of algae, fungi, and bacteria, but these living beings have very little to do with the profusion of a natural blue hue.

Blue is the last color to appear in the natural world, and the last to be developed and produced by Humans in the Anthropocene. Color systems used by liverworts (furanoflavylium), mosses and ferns (3-deoxyanthocyanins), and angiosperns (anthocyanins) are chemically identical species with the same sequence of chemical reactions, but only the anthocy... See more

In conclusion, the blue color only appeared many million years after the first plants color systems and only through the anthocyanins, Fig. 3.

Blue was the last color to diffuse in Nature and the last to appear in many of the Humans’ discoveries.

Some authors consider the possibility of Tekhelet, the most sacred of biblical colors in Judaism, be a blue or purple dye derived from Tyran purple [29,30]

While less studied, structural color has also been reported in plants [7,10,12]. In plants, these optical effects arise from the multilayer interference of two or more materials with different refractive indexes, or by stacking layers of cellulose microfibrils with differing orientations forming a helicoid structure similar to a liquid crystal... See more

Copigmentation is the result of the non-covalent interactions with different species of the flavylium multistate, in particular flavylium cation and quinoidal bases, with other compounds, mainly phenolic acids and flavonoids [8,43,45]. The copigmentation is achieved by π−π stacking as shown in Scheme 8. Many examples of copigmentation can be found... See more

Michel Pastoureau, “ Contrary to what one might imagine, the social, artistic and religious uses of the color blue do not reach back into the mists of time .”