2 weeks Ago By Sahan Weerasooriya
Use of colours in pre-historic era Humans have been long fascinated by colour, which has played a significant role since the beginning of human civilization. Ancient people had painted caves even before they settled in houses. Cave paintings were created during the stone age from 10,000 to 40,000 years ago.
Primitive artists used natural materials available to them to mark their territory, beautify their surroundings, and tell their stories. For thousands of years, paints were handmade from ground mineral-based pigments. Ochre, a natural pigment which comes in shades of red, yellow, orange and brown, was the first pigment used by humans, in the Middle Stone Age of Africa.
Ochre, also called hematite, is found all over the world and has been used by nearly every prehistoric culture, whether as paint on caves and building walls, for staining of pottery or other types of artifacts, or as part of a burial ritual or body painting. Man’s irresistible desire to create pigments was not without untoward consequences. For instance, in 1,775, Carl Wilhelm Scheele, a Swedish chemist, invented a bright green pigment, but it was laced with the deadly poisonous chemical arsenic; it was cheap to produce, but dangerous for artists and patrons alike.
However, the French emperor Napoleon Bonaparte was so fascinated by and passionate about this colour, he wanted his bedroom wallpaper painted with Scheele’s Green. Historians believe that the green pigment used in the wallpaper caused his untimely death in 1821 at the age of 51 due to cancer. By the end of the 19th century, Paris Green—a mixture of copper and arsenic—replaced Scheele’s Green as a more durable alternative, enabling Claude Monet, Paul Cézanne, and Pierre-Auguste Renoir to create vivid, emerald landscapes.
It is also toxic, and thus has also been used as a rodenticide and insecticide. The blindness which Monet subsequently succumbed to may have been due to the toxicity of Paris Green, which was banned in the 1960s. The Egyptians artists added binders such as eggs, resins and beeswax to pigments so that the paint would adhere to plaster and began painting on it.
Hence, Egyptian tombs made of limestone were covered with plaster that was painted using six colours: charcoal black, red ochre, yellow orpiment, brown ochre, blue azurite, and green malachite. Natural mineral pigments were dug from the earth and shaped into sticks that were used as chalks by artists including Leonardo da Vinci, Michelangelo, and Rembrandt. Dyes made from plants were also used in artwork in the Mediterranean region.
By the mid-nineteenth-century, watercolors became available for sale to the public. Since the 1940s, technological advances have produced synthetic pigments and chemical processes for paint making which greatly contributed to expanding the once mineral-based limited colour palette to all the colours of the rainbow. Since then, colour-based industries have grown progressively in the world and the worth of the paint and coatings industry and of colour cosmetics industries in 2023 amounted to around $ 180 billion and $ 80 billion, respectively.
Physics of colour and vision In the 1660s, English physicist and mathematician, Isaac Newton, demonstrated that clear white light was composed of seven visible colours. Johann Wolfgang von Goethe in 1810 published his treatise on the nature, function, and psychology of colours titled “Theory of Colours”. One of his most radical points was a refutation of Newton’s ideas about the colour spectrum, suggesting that darkness is an active ingredient rather than the mere passive absence of light.
Though his work was dismissed by a large segment of the scientific community, it remained of intense interest to a cohort of prominent philosophers and physicists, including Arthur Schopenhauer, Kurt Gödel, and Ludwig Wittgenstein. Colour springs from the alchemy of light and perception. Light, an ethereal wave of electromagnetic radiation, spans a spectrum visible to human eyes from approximately 380 to 750 nanometers.
As light touches an object, it may be reflected, absorbed, or transmitted, with the reflected wavelengths crafting the hue perceived by the eye. This interaction is interpreted by the brain, transforming raw light into the rich palette of the world around us. The human eye, a wondrous instrument, houses three types of photoreceptor cells known as cones, each attuned to different wavelengths of light: S Cones: Sensitive to short wavelengths, peaking around 420 nm, endowing us with the perception of blue.
M Cones: Responsive to medium wavelengths, peaking around 534 nm, allowing us to see green. L Cones: Tuned to long wavelengths, peaking around 564 nm, revealing the red hues. Human beings can only see the colours that these receptors can receive.
Together, these cones create a symphony of signals that the brain harmonises into the countless colours we perceive, enabling us to distinguish millions of shades. Nature’s creatures possess a diversity of vision, often surpassing human capabilities. Birds and insects, for instance, enjoy a tetrachromatic[DC1] vision (having four types of cone cells in the eye to perceive colour), with an additional type of cone sensitive to ultraviolet (UV) light, unveiling a hidden spectrum invisible to human eyes.
Many bird species use UV signals for mating, navigation, and foraging. Colours are ‘illusions’ People are quite interested in and passionate about colours; thus, they generally make an initial judgment about a product, person, or environment within 90 seconds, and a significant proportion of this assessment, i.e.
60-90%, is based on colour. This shows how strong the influence of colour on perception and decision-making is. Despite this extraordinary experience of colour perception, all colours are ‘illusions’ in the sense that they do not belong to objects independently of how these are perceived.
Neither objects nor lights are coloured ‘in themselves’, but are seen as coloured as a result of neural processes and perceptual mechanisms. In fact, the physical properties of colours are different from the way colours are perceived. For example, take a yellow sunflower; it absorbs the blue, red and other colour energy waves, and then reflects back wavelengths that appear yellow.
The colour receptors in our eyes then translate the flower’s wavelength into its colour and send that to our brain. Blue colours in animals are not caused by chemical pigments, but rather by physics and the way light bounces off a surface. Blue-winged butterflies have layered nanostructures on their wing scales that manipulate light layers, cancelling out certain colours and projecting the fluorescent blue colour that we see; thus, they are called structural colours.
Another classic example of structural coloration is the peacock’s feather. The microscopic structures in the feathers manipulate light to produce brilliant blues and greens that shift and change as the viewing angle alters. Thus, blue butterflies, roses, and peacocks aren’t actually blue and our eyes have duped us (Fig.
1). Effects of colour on human behaviour and wellbeing People have long understood the power of colour over moods and well-being. Colour was used in ancient Egypt, China, and Greece to evoke emotions, aid in spiritual practices, and treat a variety of conditions.
Many ancient civilizations, such as the Egyptians and Chinese, embraced the belief that colours possessed healing properties and could be harnessed for therapeutic purposes. This practice, known as chromotherapy, involved the use of specific hues to treat various ailments and promote overall well-being. Colour is a multidimensional concept which goes beyond visual appeal and aesthetic beauty.
It encompasses physical, psychological, cultural, symbolic, artistic, aesthetic and scientific dimensions, including physiological. The aesthetic beauty of colour has added a mesmerizing and exciting tapestry to nature and it is inconceivable to imagine a world without colour. Leigh Hunt (1784–1859), prolific English poet and journalist, said “Colours are the smiles of nature”.
Colour can affect humans in manifold ways ranging from psychological, physiological, cognitive to emotional, behavioural, healing etc., thereby having a profound influence on their mood, creativity, productivity, health and happiness. In addition, it has a remarkable power not only to heal, rejuvenate and inspire, but also to instill a sense of peace and harmony in us.
Colour is also a powerful means of communication and a defining aspect of human experience, influencing our perceptions and preferences, and interactions with the world. Therefore, extensive studies have been carried out on those aspects which have led to the emergence of disciplines such as Colour Psychology, Colour Chemistry, Colour Therapy and Visual Ergonomics. Colour can potentially be a powerful source of inspiration, delight, tranquility and solace when used in the right manner for the right place for the right purpose.
However, people generally apply colours purely based on the visual and aesthetic appeal, without a proper understanding of the profound impact that colour can have on people – their performance, experience and wellbeing. Therefore, the use of the right colour for a given place is crucially important in order to provide a more relaxed, congenial and harmonious living environment which goes beyond the aesthetic appeal. Here, it is important to explore the world of colour psychology without diving into technicalities The colours you choose for your walls, furniture, and the decorations of your bedroom can influence your mood.
A bedroom painted in calming tones, e.g. in light blue, might help you to unwind, and create a feeling of serenity.
It is not recommended to paint the bedrooms in dark shades of blue as it could interfere with sleep. Similarly, the blue light emitted by electronic screens could produce a similar effect. Therefore, it is not advisable to work on the computer or watch film on electronic screens for long hours prior to retiring to bed.
Because the blue light gives the impression to the brain that it is daytime, the body stops releasing the sleep hormone Melatonin. On the other hand, light shades of amber may promote the release of Melatonin helping us to wind down and prepare for sleep in nature’s way. Feeling relaxed As blue light causes people to feel relaxed, it has led countries to add blue street lights in order to decrease suicide rates.
In 2000, the city of Glasgow installed blue street lighting in certain neighborhoods and subsequently reported the anecdotal finding of reduced crime in these areas. A railroad company in Japan installed blue lighting on its stations in October 2009 in an effort to reduce the number of rail suicide attempts (Fig. 2).
Blue is often associated with calmness and serenity and is not naturally associated with food; hence, it can make food appear less appetizing and appealing and reduce the desire to eat. Therefore, blue is generally considered an appetite suppressant and eating off a blue plate could help to reduce overweight and obesity. Walls of cafés are generally painted in warm, earthy tones like brown or terracotta which evoke a sense of comfort and homeliness.
It helps the customers to settle in with a cup of coffee and a good book to spend some relaxing and rewarding time in a congenial ambience. On the other hand, some fast-food chains use red and yellow in their logos and external and internal walls in order to create a vibrant and exciting environment. It not only attracts attention, promotes quick decision making and creates a sense of excitement and urgency, but also stimulates appetite and encourages lively discussion.
Though such colours attract both children and adults to fast-food restaurants, they may not wish to stay long in such an ambience after partaking of food, unlike in a coffee shop. Similarly, a kitchen with lively colours could energize you during meal preparation. (Figure 2) Blue-winged butterfly (Source: https://pixabay.
com/photos/butterfly-insect-animal-142506/) (left) and peacock (Source: https://www.photowall.co.
uk/peacock-feathers-poster ) (right) Even when designing websites, careful attention is paid not only to aesthetics, but to emotions that need to be evoked. When a company designs a new website, it carefully selects colours with this in mind. They might use blue for trust, green for growth, and orange for enthusiasm, creating a website that feels inviting and reliable while encouraging action.
Architect William Ludlow advocated pale pastel blues and greens in hospitals for therapeutic purposes. The walls of hospitals are often painted in soft, calming colours like pale green or light blue which help to reduce stress and create a healing environment. Colour can enhance or impair learning, morale, performance and the behaviour of students.
It can affect students’ attention span, and perception of time. Visual stimulation rewires the brain, making stronger connections while fostering visual thinking, problem solving and creativity. It has been shown that the cold-coloured walls, such as blue and green, produced the highest levels of relaxation and pleasure, while the warm-colored walls such as yellow and red had the better attention and learning performance.
And the white-walled classroom had the lowest subjective evaluation and the worst learning performance. Classrooms when painted with bright yellow — the colour of happiness and optimism – spark creativity and enthusiasm and makes learning more joyful. That’s why some educational spaces use yellow in order to foster a lively and energetic environment.
School buses are generally painted yellow the world over for safety and visibility. Yellow colour is in the middle of the visible spectrum so that it strikes the cones (photoreceptors) of the eyes from both sides equally. That makes it almost impossible for anyone to miss a school bus even when it’s in one’s peripheral vision or under poor day light conditions or in bad weather.
Fitness spaces Exercise rooms and fitness spaces are generally painted in bright orange which exudes energy, motivation and vitality, encouraging movement and activity. It helps to keep the energy high and spirits lifted. Studies have shown that red causes a significantly greater response in heart rate, respiration, brain wave activity, and other nervous system functions than green or blue.
In addition, red decreases the perceived size of rooms and space and prompts a sense of warmth. Lush greenery in a park or a natural habitat has a refreshing and rejuvenating effect, creating a sense of harmony and tranquility. Besides, the choice of colour of clothing reflects and affects your mood and if you are feeling upbeat and confident, you might pick a vibrant red shirt or dress.
On the other hand, if you seek comfort and tranquility, you may settle for soothing shades of blue, green, etc. Choice of colour for prisons is of prime importance as it affects the mood of inmates. When colour is used properly in prisons and jails, it can lessen overall tension and conflicts and make the places more comfortable for the inmates to live and work in.
Based on the research carried out, bright colours are recommended in the prison, with green and blue colours being the best rated because people perceive them as soothing, stimulating, pleasant and safe. Yellow is also acceptable because the prisoners perceive it as a bright and cheerful colour. Painting the walls of the room with soft shades of yellow and green (kiwi color) was seen by the prisoners as “refreshing”.
In all these cases, colour psychology is at play. Therefore, colours play a significant role in shaping how we feel and behave; thus, they are not just pretty hues, but are the emotions painted onto the canvas of our lives. Hence, colour psychology is like a storyteller that sets the mood and tone of a space, a product, or even a piece of clothing.
It’s the silent language that whispers to our emotions, shaping our experiences without us even realizing it. However, these associations between colours and emotions are not universal, but are influenced by cultural, historical, and personal factors. Understanding colour psychology can help individuals and businesses harness the power of colour to evoke specific emotions and convey messages effectively.
Whether in branding, interior design, fashion, or art, colour plays a central role in shaping our perceptions and experiences. It’s a fascinating aspect of our world that continues to intrigue and inspire creativity in various fields. Further information in this regard is found in the book titled “The Power of Colour: Enhancing Human Wellbeing and Unleashing Human Potential” edited by Ranjith Senaratne and Raj Somadeva.
It emanated from a conference conducted by the Sri Lanka Association for the Advancement of Science and includes contributions from a multidisciplinary team comprising artists, architects, engineers, biologists, environmentalists, psychiatrists, musicians and scientists. Concluding remarks Though the manifold effects of colour on humans have been recognized from time immemorial, there is very little appreciation and understanding of those effects on humankind and how these effects could be harnessed to enhance and enrich human wellbeing, including life experience, productivity, performance, satisfaction, memory and creativity. Because of the significance of colour on humans, disciplines such as Colour Psychology, Colour Chemistry, Colour Therapy and Visual Ergonomics have emerged which have assumed considerable importance in day-to-day life.
A good grasp of Colour Psychology helps to create a psychologically satisfying, aesthetically pleasing, vibrant and energetic space, or a calm and tranquil environment by selecting the appropriate shades of colours depending on the need and occasion. This is crucially important in a fiercely competitive globalized environment characterized by anxiety, tension, disquiet and chaos where people are leading a stressful, restless and agitated life in a fast-paced world. In the circumstances, creating a relaxed, congenial and harmonious environment at home as well as at the workplace by painting the living and working environment with appropriate hues is of prime importance.
This need is paramount and should be addressed as a matter of great importance. Then only could we embark upon a colorful journey and paint our world with appropriate vibrant hues in order to unearth the boundless potential and transformative power that lies within us. However, there is a dearth of competent professionals, particularly in Sri Lanka who can proffer the right advice and guidance to clients in selecting appropriate colours for specific places such as the living room, bedroom, dining room, reading room, exercise room etc.
in homes and public places such as hospitals, restaurants, coffee shops, gymnasiums theatres, prisons etc. for the human wellbeing. This issue has been further exacerbated due to hardly any academic interaction and collaboration, particularly between the Faculties of Arts, Science and Medicine.
The course unit system (CUS) developed in the USA enables students to pick and choose course modules from diverse fields so as to create complementarity and synergy; this in turn, leads to producing well-rounded and well-grounded creative graduates equipped with multiple competencies to address real-world issues more effectively. Though the CUS was introduced in our universities over 20 years ago, because of the heavy compartmentalization and fragmentation, course modules for degree programmed of a given faculty have been selected mainly from among the modules offered by the faculty concerned, thereby not deriving the key expected benefits from the CUS. Consequently, Sri Lankan universities have been hardly able to develop any cross-faculty academic programmed such as Colour Psychology, Colour Therapy, Music Therapy and such like.
Therefore, it is imperative to make necessary interventions so as to facilitate and promote interfaculty degree programmed in Sri Lanka universities, paving the way for the development of such academic offerings jointly by the Faculties of Arts, Science, Medicine, Architecture etc. Moreover, cooperation and collaboration between faculties are needed to effectively address complex real-world issues such as SDGs which demand a holistic trans-disciplinary systems approach. Hence, the earlier such interventions are made, the better.
by Emeritus Professor Ranjith Senaratne University of Ruhuna, ([email protected]).
