There are many opinions about colour and its influence on our emotions, but proof can sometimes be thin on the ground. Here we present five fun evidence-based tales of colour perception and mood.

Kandinsky’s postcards

In 1923, Bauhaus colour theorist Wassily Kandinsky sent out 1,000 postcards to alumni of the Weimar School asking them to associate the primary colours of red, blue and yellow with three primary shapes – a triangle, a square and a circle. Respondents to his survey overwhelmingly associated yellow with the triangle, confirming his belief in colour-form associations. 

Later studies have been less conclusive, and some researchers have suggested that Kandinsky had the condition synaesthesia, leading to enhanced perceptual experiences. You can take Kandinsky’s test yourself here.

The Pink Effect

In 1979, Baker-Miller Pink, also known as Drunk Tank Pink or just P–618, was proven to reduce aggressive behaviour in an American prison. Created by mixing one gallon of white emulsion with one pint of red gloss paint, the colour was the brainchild of biosocial researcher Alexander G Schauss. 

After observing the effects of the shade on himself, Schauss persuaded a Seattle correctional facility to paint its holding cells in the colour, naming it after the institution’s two directors. After 156 days no incidents of hostile or aggressive behaviour had been reported. The colour was subsequently used at other prisons and even the away-team locker rooms of some US sports venues. It should be noted that more recent studies have failed to replicate the Pink Effect.

Healthcare, mood and colour

When researchers at a hospital in Wuppertal, Germany set out to prove that colour can have an impact on patient recovery, the findings were remarkable. In the 2019 exercise, patients and staff at an intensive care facility took part in workshops where emotions around colour were discussed and new palettes chosen by consensus. Participants also completed questionnaires recording their mood before and after new colour schemes were introduced. 

At the end of the study almost a third of patients reported increased satisfaction with their nursing care, while 55% felt their room setting was more private. In one ward, consumption of medication decreased by 51% with the launch of its new colour scheme.

Babies can categorise colour

Babies are born with around 5% of the visual acuity of adults – it takes a while for stereoscopic vision to kick in, with infants unable to perceive depth until they’re a few months old and faces only at around 30cm or closer. But researchers have found that even babies can categorise colour. 

In a study from the Sussex Colour Group and Baby Lab at the University of Sussex, 170 babies were recruited to find out how many colour categories they could see. The findings identified five – red, green, blue, purple and yellow-brown. Perhaps surprisingly, pink was not part of the spectrum.

Ketchup and mustard theory

The ‘Ketchup and Mustard’ theory is a marketing concept influenced by the belief among some psychologists that colours affect mood and feelings, including hunger. It suggests that the colour red kick-starts emotions of warmth and cheer while yellow elicits happiness and excitement – the perfect combination to stimulate appetite. 

There may be no evidence to back up this theory but it certainly explains the preponderance of this colour scheme in fast food environments. But be warned – according to one US study of perceived colour meanings, yellow is also associated with low-quality and inexpensive products and red with the emotion of anger.