Blue is the most common colour in the logos of Fortune 500 companies. Facebook, Samsung, Ford, American Express, Dell, PayPal, Visa, Twitter, LinkedIn. The list goes on at length.

This is not a coincidence, and it is not just fashion. Blue carries a set of near-universal associations that make it extraordinarily useful for large organisations. Trust. Reliability. Stability. Calm authority. These associations are partly cultural and partly rooted in the natural world, where blue skies signal safety and clear weather, and still blue water signals calm.

For banks and technology companies in particular, blue does a specific job. It signals that this organisation is dependable, that your money or your data is safe here, that nothing unpredictable is going to happen. In categories where trust is the primary purchase driver, blue is almost the default answer.

Facebook's founder Mark Zuckerberg has said publicly that the platform is blue because he is red-green colour blind and blue is the colour he sees most vividly. Which is a reminder that even the most analysed branding decisions sometimes have surprisingly human explanations.

Red: appetite, urgency, and energy

Red is the colour of Coca-Cola, YouTube, Netflix, Lego, and Target. It is also the colour most strongly associated with appetite, which is why it dominates the fast food industry alongside yellow.

Red increases heart rate and creates a sense of urgency. It demands attention in a way that other colours simply do not. In evolutionary terms, red signals ripeness, danger, and high energy states. It is a colour the brain is primed to notice and respond to quickly.

For food and entertainment brands, that urgency is an asset. You want people to feel hungry, excited, and ready to act. Red does not invite contemplation. It pushes toward action.

There is also something worth noting about red and memory. Studies consistently show that red objects and environments are recalled more vividly than those in cooler colours. For a brand trying to be memorable in a crowded market, that recall advantage is significant.

Yellow and orange: optimism and accessibility

McDonald's golden arches. IKEA. Snapchat. Amazon. Subway. Yellow and orange cluster around a consistent set of brand values: friendliness, affordability, energy, and optimism.

Yellow is the most visible colour in daylight conditions. It is the first colour the human eye notices, which is why it appears on taxis, warning signs, and school buses. For brands, this visibility translates to approachability. Yellow says: we are easy, we are cheerful, we are not intimidating.

Orange sits between the urgency of red and the optimism of yellow and tends to carry connotations of creativity, enthusiasm, and value. Brands that want to feel energetic but not aggressive, or affordable but not cheap, often reach for orange. It is a colour that works hard without the intensity of red.

Amazon's smile logo uses orange specifically because research showed it felt warm and approachable across a wide range of cultures and demographics. For a platform trying to serve everyone, that broad legibility matters enormously.

Green: nature, health, and permission

Whole Foods. Starbucks. John Deere. The Body Shop. Spotify. Green is the colour of growth, nature, health, and, in many Western cultures, permission. Go. Safe. Approved.

As consumer interest in sustainability and wellness has grown over the past two decades, green has become an increasingly strategic choice for brands wanting to signal environmental responsibility or health credentials. The risk, well documented in marketing research, is greenwashing: brands that adopt the colour without the substance behind it tend to be seen through quickly.

Starbucks uses a deep, saturated green that feels premium rather than purely natural, which is a deliberate positioning choice. The shade matters as much as the hue. Pale, desaturated greens feel clinical or budget. Deep, rich greens feel considered and trustworthy.

Purple is the colour of luxury, creativity, and mystery. Cadbury, Hallmark, and Milka use it to signal indulgence and premium quality. But you will almost never see it in mass-market food branding.

The reason is fascinating. Purple does not exist widely in nature as a food colour. There are very few naturally purple foods that humans have historically eaten, and the ones that do exist, such as certain berries, are often associated with fermentation or overripeness. The brain does not associate purple with appetite the way it does red, yellow, or orange. In food contexts, it can actually suppress hunger.

For a chocolate brand positioning itself as an indulgent treat rather than a staple food, that suppression of appetite is not a problem. But for a fast food chain trying to move volume, it would be a disaster.

Once you understand colour psychology in branding, you cannot unsee it. The supermarket aisle becomes a study in applied colour theory. The apps on your phone form a palette that tells you something about how each company wants you to feel. The logos you have glanced at thousands of times reveal the decisions behind them.

Colour is never just decoration. In branding as in nature, it carries meaning, triggers response, and communicates things that words take much longer to say.

That is something we think about constantly at CMY Cubes. Cyan, magenta, and yellow are not arbitrary choices. They are the three colours that between them can produce almost every other colour that exists. They are the building blocks. The irreducible starting point.

Which might be the most honest thing a colour brand could ever put in its logo.