Van Gogh’s Starry Night Over the Rhône (1888). Blue used to create a mood or atmosphere. A cobalt blue sky, and cobalt or ultramarine water.

Amazing Color Blue Pictures to Inspire You

And its uses in the world… of architecture, art and fashion.

I have been thinking…Why do People Think Blue World is a Good Idea?

Your Blue World May Never Works Out the Way You Plan.

This blue world here is not the same as your blue world.

Blue is one of the primary colors of pigments in painting and traditional color theory, as well as in the RGB color model. It lies between violet and green on the spectrum of visible light. Wikipedia.

It creates a mood or atmosphere. A cobalt blue sky, cobalt or ultramarine water.

And in architecture…Where you see blue in your city? In the sky or in a blue sea?

Or on walls?…look at this blue walls in Morocco. What about your house painted in blue?

A blue house in Chefchaouen, Morocco.

Blue City. Chefchaouen, Morocco. From architecturehub

Blue door. Blue City, Marocco.

And the blue facade of the One World Trade Center, New York.