English film-maker Derek Jarman wrote about flowers and colour with erudite tenderness. His last book was Chroma. A Book of Colour – June ’93, a treatise on colour written a year before an illness linked to AIDS took his life. Chroma is a poignant elegy made up of observations on how pigments are obtained, quotes on art and philosophy and biographical notes that oscillate between memoranda of a still searing past and a chronicle of the progression of a disease that was consuming him, slowly and excruciatingly. At a time when he had to take dozens of drugs to stay alive, he wrote:

‘The great dye factories experimenting in scientific and artificial colour in the nineteenth century. The invention of malveine, aniline, fuchsin, the red dyes, were the foundations of Bayer and Ciba, and many other multinationals. Colour was turned into explosives. The fiery orange of nitre. Not only were they making explosives but they were also making drugs. The pills you swallow came from the dyers’ works. In the antiquity, colour (chroma) was considered a drug (pharmakon). Colour therapy’.

This insightful observation, which points out the aesthetic, economic and political dimension of colour in medicine, is based on an excerpt of the brief A history of colors by Manlio Brusatin. The Venetian historian continues by asserting that hygienic white, imposed from the eighteenth century onwards, ‘presupposed a [...] pragmatism in which all other colors were considered in the light of a clear, civilizing mind-set, extending into shadowy areas an overpowering effort towards cleanliness’. What he does not mention is that whitewash, despite being the flagship colour for modern medicine, fell into crisis within institutions, for practical reasons precisely.

In May 1914, Harry M. Sherman, an eminent doctor at San Francisco Polyclinic, published an article in which he explained the virtues of the colour ‘spinach green’ for operating rooms. This shade of green, which complements the red of the haemoglobin in vertebrate animals’ blood, turned out to be the ideal replacement for white, which reflected too much light and tired out the surgeons’ eyes. ‘Spinach green’, present in all hospitals and veterinary clinics, was a shade that came from beneath the skin. A symbiosis between aesthetics and biology that produced a result that was radically opposed to the determinism of gender, class, race and species advocated by the hygienic white of the ‘civilizing mind-set’. Over time, this revolutionary green was accompanied by a conciliatory sky blue, followed by other colours.

In the second half of the twentieth century, the use of colour became a key consideration in medicine, along with new materials and the exponential progress of technology. Colour was assigned a psychological function that, when applied to graphics, uniforms and architectures, helped to characterise the various special units contained in increasingly complex medical centres. In parallel, images were incorporated into the detection and description of the agents that cause illnesses, thus modifying our understanding of hospital medicine forever.

Today, images and colour are more important than ever. Robotisation and remote access to macrodata determine a reality in which the surgeon and the patient can easily be miles apart during an operation. In February 2019, the first 5G-assisted telementored surgery took place. The operation was carried out in the Optimus operating room at Hospital Clínic in Barcelona. At the moment, this is the most advanced operating room in the world; an organ for total connectivity: an eye without a tear duct whose retina records the smallest details and whose iris is an immense multicoloured aureole that dyes the whole space with subtle light variations. The ‘Internet of Things’ operating room has displaced the old tile-clad, whitewashed theatre. The kaleidoscopic staging of Optimus is the final form of a close symbiosis between medicine and colour that, in Western culture, dates back to classical antiquity.

In Illness as Metaphor, Susan Sontag proposes the concept of ‘dual citizenship’, with which we live in the kingdom of the well and the kingdom of the sick. If, as we have seen, the history of the pharmaceutical industry can be condensed into the colour of a pill; the anodyne shade of hospital green holds unprecedented political potential; and medicine is anticipating a hypermediated care paradigm, now more than ever we must examine the nature of, and the representations used by, the customs points that issue passports from one kingdom to the other, with a view to creating speculative narrations that constitute alternatives to the markedly positivist discourse around technological progress in medicine.