Blue is one of the three primary colours of pigments in painting
How is blue made?
Blue lies between violet and green on the spectrum of visible light
What other forms is associated with blue?
objects  at s distance appear more blue because of another optical effect called atmospheric perspective.
Is blue related to royalty,like they say blue blood?
Well it all depends on the reference in question, it relates to royalty
How is blue perceived by different tribes around the world?
Middle Ages, European artists used it in the windows of Cathedrals.
It means that blue had had a long lasting significance