My favorite color is blue.  How about you?
Mine is red. But there are some beautiful blues that l love.
Blue and red are primary colors of pigments in many paintings.
I hadn't noticed that. There are so many shades of blue, so I can see how that happens.
Blue
Blue is one of the three primary colours of pigments in painting and traditional colour theory, as well as in the RGB colour model. It lies between violet and green on the spectrum of visible light. The eye perceives blue when observing light with a dominant wavelength between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; azure contains some green, while ultramarine contains some violet. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering.
but show a steady progression away from objects and external reference. His work progressed from compositions of geometrical shapes in the 1940s to works in different shades of the same color (all red, all blue, all white) in the 1950s. 
Reinhardt is best known for his so-called "black" paintings of the 1960s, which appear at first glance to be simply canvases painted black but are actually composed of black and nearly black shades. Among many other suggestions, these paintings ask if there can be such a