The concept of colour psychology, also known as chromotherapy, was first proposed by Nicholas King Dashabia. The earliest studies of colour date back to ancient times, and research into colour has continued into the modern era.

In 1979, an American naval officer named Baker Miller conducted an experiment in prison to investigate the effect of colour on violent behaviour among prisoners. The researchers applied pressure to the prisoners’ arms and asked them to resist this pressure, whilst showing them cards of two different colours: one blue and one pink. Initial results indicated that when the blue card was presented, the prisoners resisted with greater force; when the pink card was presented, their resistance weakened.

However, these findings were deemed inconclusive due to the influence of the researchers’ subjective bias; when researchers knew the colour of the card to be presented, they developed a preconceived notion and naturally interpreted the results in line with their expectations.

Subsequently, they mixed one pint of red paint with one gallon of white paint to create a lovely shade of pink, and painted the prison cell walls in this colour to observe the effect of a ‘pink prison’ on prisoners’ violent behaviour. However, the research findings indicated that the pink walls had no effect on the prisoners’ violent behaviour. Although this series of experiments was not successful, it attracted widespread public attention, and the colour was later named ‘Baker-Miller pink’, also known as ‘pudding pink’.

In 2014, a researcher named Oliver Genschow and his team visited a high-security Swiss prison with the aim of replicating the experiment. Before the experiment began, they provided the prison officers with relevant training and supplied them with an aggression rating scale to measure the prisoners’ behaviour, to help the officers assess the prisoners’ behavioural indicators.

Prisoners who breached the rules were randomly assigned to one of three types of cells: those painted entirely pink, those with grey walls, or those with a pink ceiling. The researchers sought to demonstrate that prisoners confined to pink cells would exhibit a significant reduction in aggression; however, regrettably, following a series of rigorous experiments, it was found that prisoners’ aggression levels decreased within three days of being placed in any of the three types of cells.

Although the researchers did not obtain the experimental results they had hoped for, this has not hindered research into colour; in fact, many meanings associated with different colours have already been identified.

Red

Red has the longest wavelength of all colours. It provides a strong visual stimulus, serving to attract attention and evoke feelings of excitement, enthusiasm and tension. At the same time, it conveys an impression of vitality, maturity, joy and festivity; elements of red can be found in many logos, flags and promotional graphics.

As red is associated with blood, it is also widely used in many warning signs, such as traffic lights and fire hydrants. In bedrooms and studies, one should avoid using bright red as the dominant colour, as it can subconsciously induce a sense of tension.

People who favour red tend to have resolute, confident, strong, passionate and exuberant personalities. They are energetic, have a distinct sense of self, prioritise efficiency and are highly capable.

Yellow

Yellow is the brightest of all colours. As such, it conveys a sense of vitality, hope, joy, brightness, warmth and gentleness.

People who favour yellow generally give off a sunny, positive vibe; they have lofty ambitions, enjoy sharing, and bring joy to others, though they often overlook minor details in daily life.

Blue

Blue is the colour of the sky and the sea; it is also a cool colour, which helps to alleviate tension and has a calming, soothing effect. Blue lighting has been shown to be effective in treating insomnia and lowering blood pressure. Due to its unique calming properties, using blue in the bedroom can help people fall asleep quickly, and blue bed linen can have a similar effect.

Blue also evokes associations with the spiritual realm; it conveys notions of sublimity, profundity, purity, transparency and wisdom. Many technology companies favour blue because it represents technology and rationality.

Those who like blue yearn for a peaceful and stable life; they have principles and convictions, enjoy deriving a sense of achievement through their technical skills, and give the impression of being trustworthy.

Green

Green is the colour of plants, evoking feelings of steadiness, comfort, tranquillity, hope, vitality and fulfilment. Green possesses the calming qualities of blue and the vibrant qualities of yellow; it is the most soothing colour for the human visual system, helping to regulate the optic nerves and relieve eye strain. Green is also the colour of environmental protection, and many eco-related logos use green to convey this message.

People who favour green are level-headed, manage themselves and their time well, are not easily overwhelmed by pressure, and possess strong convictions, though they may occasionally be overly stubborn.

Purple

Purple has the shortest wavelength of light and evokes feelings of nobility, superiority, luxury, elegance, fluidity and restlessness. In ancient times, purple was a rare colour and was therefore widely used amongst the nobility; later, it came to be regarded as a symbol of power.

Those who favour purple tend to be rather sentimental and emotional, with a vivid imagination. Working in the arts allows them to give free rein to their boundless imagination, though they may occasionally harbour unrealistic ideas.

Orange

Orange is a colour closely associated with the sun, evoking a sense of vitality and energy; it is also the colour of autumn, the harvest season and a festive atmosphere. Orange can also stimulate the appetite, which is why many catering businesses incorporate elements of orange into their design.

People who love orange are optimistic, lively, passionate, cheerful, enjoy socialising and are very proactive in their endeavours.

White

White reflects all light; in other words, it is composed of the entire spectrum of visible light. It conveys a sense of brightness, cleanliness, clarity and purity, whilst also creating a visually airy and uncluttered impression. Using white in small spaces can make a room appear brighter and more spacious. 

White is used extensively in hotels and hospitals, primarily because it emphasises the hygiene of the environment, putting people at ease.

People who favour white tend to be pure, peaceful and calm; they appreciate beauty, possess ideals and aspirations, and are perfectionists.

Black

Black refers to the absence of any visible light within the visual spectrum; in other words, black is the colour of no colour. Black conveys an impression of elusiveness, seriousness and solemnity, whilst also evoking feelings of gloom, fear, melancholy and negativity. As black absorbs the entire light spectrum, black objects tend to feel heavier in texture; wearing black clothing can also make you appear slimmer.

People who favour black value their privacy, give off an air of mystery and are drawn to enigmatic things, though they may sometimes be prone to negative thoughts.