Shades of cyan

Cyan is the oldest and most abundant organic colour to have existed on Earth, and yet the most elusive of primary colours for human artistry. As a dye or as a pigment, cyan is one of the subtractive primaries, which combines with yellow and magenta to produce a full spectrum of reflected hues. Yet no natural dye or pigment has the perfect cyan quality of absorbing all red light, to reflect only blue and green. Until the first synthesis of mauvine dye in 1856 and phthalocyanine pigment in 1927, and their subsequent derivatives, fabrics and paints approximated the reflected-colour wheel with mixes of naturally-sourced blue, yellow and red colourants. This natural chromatic palette leaned heavily towards warm colours and earth tones. Greens were muted or olive, not bright and vibrant, and blues could neither extend into brilliant violets, nor emulate the vivid cyan of tropical waters or gemstone turquoise. The completion of the subtractive-colour wheel – by chemists using products of the Industrial Revolution – coincided with a revolutionary shift in Western pictorial art beginning c. 1860, towards impressions of light, saturated colours and expressive styles.

C.P. Doncaster, Timeline of the Human Condition, star index