Hi, the sky is so pretty and blue today. Blue is my favorite color. What's yours.
I really like blue as well. Especially blues that have an ultramarine shade, with lovely violet in it. 
There really are a lot of different shades of blue, that's for sure.
Very true. It's kind of cool that there is something called the Rayleigh scattering that causes the sky to be blue and the dark color of the sea. It's an optical effect of sorts.
I think it was first produced by the Egyptians who figured out how to create a pigment for their decorative arts.
cellular density of the stroma. The appearance of blue and green, as well as hazel eyes, results from the Tyndall scattering of light in the stroma, a phenomenon similar to that which accounts for the blueness of the sky called Rayleigh scattering. Neither blue nor green pigments are ever present in the human iris or ocular fluid. Eye color is thus an instance of structural color and varies depending on the lighting conditions, especially for lighter-colored eyes.
The brightly colored eyes of many bird species result from the presence
Theo, "'Cobalt [blue] is a divine colour and there is nothing so beautiful for putting atmosphere around things ..."
Van Gogh described to his brother Theo how he composed a sky: "The dark blue sky is spotted with clouds of an even darker blue than the fundamental blue of intense cobalt, and others of a lighter blue, like the bluish white of the Milky Way ... the sea was very dark ultramarine, the shore a sort of violet and of light red as I see it