"Color" for artists

Watercolor, Rock Harbor, Orleans, 2019

I have struggled with the question everyone is asked at some time or another, "What is your favorite color?"  I guess on reflection, mine is the ice blue of a glacier I saw once in Glacier Bay, Alaska.
Its novelty makes it my favorite.  

However, as an artist, I find it best to ditch the word "color". Instead I think about the properties of the colored paints I use.  In this sense, painting becomes like cooking, where the particular ingredients and how they can be used and combined, are important, rather than some abstract concept of taste.

My favorite blues are the pigments ultramarine blue and cobalt teal, which I use in water colors and acrylics. They usually cover the blue spectrum very well for me. I also use thalo blue which has a slight greenish cast and which also comes in green(er) and a red shade, the latter close to ultramarine. Cobalt blue sometimes makes a good upper sky color.

But keep in mind that "color", as we see it, is relative.

Blue is the name we give to things we see that absorb all of the visible spectrum except blue wave lengths. But the blue we see depends on  how we see it. Blue sky at dusk is a dull blue.  But if you are walking outside from an interior lit by artificial light, the sky will appear a bright electric blue, which fades to blue-grey over a few seconds as your visual system readjusts to darker lighting conditions.

A blue crayon placed between two orange ones will give a stronger appearance than one placed between two yellow ones because our visual system is recording the wave length differences. with the orange wave length being farther away from blue than yellow.