Red is energising. Blue is calming. Yellow is cheerful. Green is restful. These claims are so widespread in design discourse, in marketing and in popular psychology that they have achieved the status of received wisdom. In the form they usually take, they are significantly overstated.

The relationship between colour and psychological experience is real. It is also far more complex, more context-dependent and more culturally variable than the simple colour-emotion mappings suggest. That complexity is worth acknowledging, not because colour psychology is meaningless, but because the meaningful claims are more interesting than the simple ones.

Colour does affect perception, emotion and behaviour. The effects depend on the specific colour, meaning its hue, saturation and brightness together rather than its name; on the context in which it appears, including surrounding colours, lighting and surface; on the cultural context of the person perceiving it; and on their personal associations.

Colour meaning is cultural

White in Western cultures is associated with purity, innocence and beginnings. It is the colour of weddings and christenings. In many East Asian cultures white is the colour of mourning and of funeral garments. Neither association is correct. Both are culturally determined.

Red in Western cultures carries associations of danger, energy and passion. In China it is the colour of luck, prosperity and celebration: New Year, wedding gifts, lucky money envelopes. In India it is associated with marriage and festivity, and a bride typically wears red. In some southern African traditions red was the colour of mourning.

These variations do not mean that colour communicates nothing. They mean that colour communicates within a cultural framework, and anyone designing across cultural contexts needs to know which associations are broadly shared and which are local.

What the research actually shows

The research is extensive and its conclusions are considerably more modest than popular accounts suggest.

Some effects are reasonably robust. Colours at the warm end of the spectrum are generally rated as more arousing, energetic and attention-getting than those at the cool end, and this has physiological correlates: warm colours produce slightly higher arousal responses under controlled conditions.

Red has been studied most. Mehta and Zhu, publishing in Science in 2009, found that red environments impaired performance on cognitive tasks requiring deep or creative thinking, possibly by triggering threat-alertness, while improving performance on tasks requiring attention to detail. Hill and Barton, in Nature in 2005, found that competitors wearing red in Olympic combat sports won marginally more often than those in blue.

Both findings are real and both are worth two caveats. The effect sizes are small, considerably smaller than popular accounts imply. And both sit within a psychological literature that has been through a serious replication crisis, so treat single striking findings with care.

The appetite claim does not hold up. The belief that fast food chains use red and yellow because those colours stimulate appetite and eating speed is repeated constantly and is poorly supported. The choice of red and yellow is better explained by high visibility and attention capture in a competitive roadside environment than by any specific appetite mechanism. The related claim that blue suppresses appetite is on the same footing and rests largely on a single much-repeated anecdote.

Colour and branding

Branding is where colour psychology has the most practical application, and where the research offers more useful guidance than elsewhere.

Colour is the most immediately recognisable element of a brand identity. It is processed faster than shape or text and retained more durably in memory.

You will very often see the figure that colour increases brand recognition by up to 80 per cent. It is worth knowing that this statistic, one of the most quoted in marketing, has no traceable source. It is usually attributed to a University of Loyola Maryland study that nobody has been able to produce. The underlying claim that colour aids recognition is sound. The number is not evidence.

Colour trademarks are real but hard to hold. Tiffany Blue and T-Mobile's magenta are registered and defended. Cadbury is the cautionary example: its registration of Pantone 2685C was struck down by the Court of Appeal in 2013, following a challenge from Nestlé, on the grounds that the description of the mark was insufficiently precise. Protecting a colour is possible and it is not straightforward.

The practical guidance from the research is less about specific emotional associations and more about three things:

  • Consistency. The same colours across every touchpoint, over long periods, to build recognition.
  • Distinctiveness. Colours that differentiate you from competitors within your category.
  • Appropriateness. Colours semantically congruent with what you actually do.

The claim that blue means trust is an observation about statistical tendency, not a causal mechanism. The brands that have built the strongest associations of trust with blue have done so through consistent appropriate use over decades, not because blue inherently conveys trust to all viewers in all contexts.

Personal colour

Beyond the research and the applications, colour is one of the most intimately personal aspects of visual experience.

People develop individual colour associations over a lifetime, connected to places, people, experiences and emotions, that are entirely personal and entirely real. The green of a childhood bedroom. The blue of a particular winter sky. The red of a specific loss. These are not cultural associations but private ones, as specific and as indelible as any sense memory.

A designer who understands that the audience brings this history to every colour choice, and that colour never arrives in a neutral receiver but in a person with a lifetime of colour behind them, is working with something more useful than a chart.

A note on method

The pattern in this article is one that recurs across this site: a real underlying effect, considerably overstated, repeated until it becomes common knowledge, with an unsourced number attached.

If that shape is familiar, it should be. It is the same shape as the Ogham tree calendar and the year-and-a-day handfasting. Marketing does it as readily as folklore does.

Sources

  • Mehta, R. & Zhu, R. (2009). Blue or Red? Exploring the Effect of Color on Cognitive Task Performances. Science, 323(5918), 1226–1229.
  • Hill, R. A. & Barton, R. A. (2005). Red enhances human performance in contests. Nature, 435, 293.
  • Elliot, A. J. & Maier, M. A. (2014). Color Psychology: Effects of Perceiving Color on Psychological Functioning in Humans. Annual Review of Psychology, 65, 95–120. The best single survey of what is and is not supported.
  • Open Science Collaboration (2015). Estimating the reproducibility of psychological science. Science, 349. For the replication context.
  • Société des Produits Nestlé SA v Cadbury UK Ltd [2013] EWCA Civ 1174, for the colour trademark case.
  • Intellectual Property Office on registering colour marks in the UK.
  • On the untraceable 80 per cent statistic, see any attempt to source it; the trail ends at citations of citations.

Related: [The Science and Soul of Colour]; [Sacred Colour]; [How to Read an Esoteric Claim]; [The Language of Flowers]