Have you noticed that red, yellow, and green are universal colours for hazard identification? From traffic lights that dictate our daily commutes to emergency signs and equipment, these colours are universally accepted symbols for warning, caution, and safety. The choice of these colours is rooted in psychology, biology, and cultural history.
The Psychology
At the core of colour selection in hazard identification is the psychological impact each hue has on the human mind.
- Red is universally associated with urgency, danger, and alertness. Its bold presence immediately captures attention, making it the ideal choice for stop signals or emergency alerts. Studies suggest that red increases heart rate and stimulates quick decision-making, a necessary reaction when immediate action is required.
- Yellow occupies a unique middle ground as the colour of caution. Positioned between the extremes of red and green, yellow signals the need for alertness without necessarily implying immediate danger. Its softer intensity compared to red allows it to function as a transitional warning.
- Green, in contrast, embodies safety, permission, and progress. It’s soothing and reassuring, often associated with nature and stability. It can mean go, conveying that conditions are safe to proceed. The human eye is particularly sensitive to green wavelengths, making it easy to see even in less-than-ideal lighting conditions. This clarity is why green is used not only in traffic systems but also to mark safe areas in emergency plans, helping people quickly identify escape routes and secure zones.
Orisent’s evacuation triggers and evacuation sirens sit on a red backboard, reflecting the urgency that a full or partial site emergency evacuation requires. Red is also the colour of the evacuation alerts that display on the control panel and smartphone app.
The Science of Visibility
Beyond psychological responses, the choice of red, yellow, and green is supported by the physical properties of light and human vision. The human eye is equipped with cone cells that are sensitive to different wavelengths of light, roughly corresponding to red, green, and blue.
Red has the longest wavelength among these, which means it can be seen clearly even from a distance or in foggy conditions. This is why emergency vehicles and stop signs frequently feature red – they need to be noticeable regardless of weather or distance. In hazardous environments, Orisent’s high visibility backboards ensure workers can see them in all sorts of environments: multi story construction sites, mining tunnels, civil works projects, stair wells.
With its intermediate wavelength, yellow offers high visibility and works well in a variety of light conditions. It does not overwhelm the senses like red can, but it still stands out against many backgrounds. Orisent’s evacuation sirens are yellow, and the combined nurse call trigger and evacuation siren backboard also features a large yellow section.
As the most prevalent colour in nature, green might seem counterintuitive when signalling safety, but its commonality tends to lend it a calming effect. Moreover, our eyes are most attuned to green light, which makes it an excellent choice for signalling that it is safe to proceed.
Orisent’s nurse call triggers use a green backboard. Green is universally associated with first aid due to its established role as a safety color and its connection to the International Organization for Standardisation (ISO) standard for first aid signs. A white cross on a green background is the internationally recognised symbol for first aid, guiding people to locations with the understanding they can call for first aid or access first aid supplies and facilities. Orisent’s nurse call alerts on the control panel and smartphone app use the same green safety colour.
Standardisation of Safety Colours
The application of these colours in everyday systems like traffic lights is a prime example of standardisation born from necessity. The establishment of a uniform colour scheme for traffic control has been critical in ensuring that drivers across the globe interpret signals in the same way.
In emergency management, the same logic applies. Designating red for emergency events, such as a red alert for a wildfire or a red zone in disaster management, instantly conveys the severity of the situation. Conversely, green areas in emergency maps and building plans indicate safe zones or routes to safety, providing clear guidance during chaotic situations. These universally recognised colour cues enable rapid decision-making, which is often critical in emergencies.
Orisent’s emergency alert systems utilise red, yellow, and green across the primary product range including evacuation triggers, evacuation sirens, nurse call triggers, the smartphone app, and the control panel. Large aluminium reflective backboards ensure devices can be seen in low light conditions from far away.
Invest in Safety
Does your workplace safety system utilise these colours? How up to date is the technology? Would a worker, site visitor, or client quickly understand what they need to do to raise an emergency alert?
Orisent’s designs work with the universal adoption of these colours, transcending language and cultural barriers to offer a simple yet profound method of conveying critical information quickly and efficiently. The emergency triggers and sirens ensure clarity and consistency where clear communication can be a matter of life and death.
Get in touch with our team today to discuss how we can work together to improve safety on your sites.