Walk onto any worksite in the UK and you’ll see a mix of fluorescent yellows, oranges, and sometimes even reds. But these colours aren’t chosen at random. Under EN ISO 20471, hi vis colour codes determine how visible a worker must be in different environments.
If you wear high-visibility clothing daily or use custom hi vis for your team understanding these colour codes helps ensure you stay compliant, safe, and easily seen.
To make things clearer, this guide breaks down what each colour means, when it should be used, and how the UK’s safety rules influence your choices.
Why Do Hi Vis Colour Codes Matter?
Hi vis colour codes ensure a worker can be clearly seen in day and night conditions. They help employers meet legal duties under the PPE at Work Regulations 1992, which require suitable protective clothing based on risk assessment.
Colour choice affects:
- Contrast with the environment
- Distance visibility
- Industry-specific requirements
- Compliance with EN ISO 20471 and other sector rules
What Colours Does EN ISO 20471 Approve?
EN ISO 20471 recognises three compliant fluorescent colours:
1. Fluorescent Yellow
The most common hi vis colour in the UK.
Best for: Construction, logistics, warehousing, highways, general outdoor work.
Why: High contrast in most daylight conditions.
Best for: Construction, logistics, warehousing, highways, general outdoor work.
Why: High contrast in most daylight conditions.
2. Fluorescent Orange
Required for certain industries.
Best for: Road workers, traffic management, vehicle marshals.
Important: Rail workers must use a specific variant known as High-Visibility Orange (RIS-3279-TOM compliant).
Best for: Road workers, traffic management, vehicle marshals.
Important: Rail workers must use a specific variant known as High-Visibility Orange (RIS-3279-TOM compliant).
3. Fluorescent Red
Less widespread, but used in environments where yellow and orange fail to stand out.
Best for: Industrial plants, ports, emergency teams in unique visibility conditions.
Best for: Industrial plants, ports, emergency teams in unique visibility conditions.
How Do Colour Codes Fit into EN ISO 20471 Classes?
EN ISO 20471 defines visibility classes based on the garment’s reflective and fluorescent coverage. Colour affects how visible the garment appears in different lighting.
Class 1 – Lowest Coverage
- Works indoors or in low-risk areas
- Typically, yellow or orange vests
Class 2 – Medium Coverage
- Suitable for roadside workers and drivers
- Often seen in orange or yellow t-shirts and polos
Class 3 – Highest Coverage
- Required for high-speed traffic areas
- Typically, full-sleeve jackets in yellow or orange
The colour chosen must still comply with the minimum luminance and chromaticity requirements of EN ISO 20471.
Colour Code Breakdown: When Should You Use Each One?
Q: When should workers wear yellow hi vis?
When general visibility is required, especially in daylight or mixed indoor/outdoor tasks.
Q: When is orange hi vis mandatory?
Orange is commonly required for anyone working near public roads. Rail workers must wear rail-specific high-visibility orange.
Q: Why would someone choose red hi vis?
Red is used when yellow or orange blend with surroundings such as autumn forestry or red clay industrial sites.
How Colour Choice Impacts Personalisation and Custom Workwear
Many companies use personalised hi vis clothing for identification and branding. The colour you choose affects:
- How well logos display
- Whether text remains visible from a distance
- Compliance (logos can’t cover reflective areas)
When ordering custom made hi vis workwear, always ensure:
- The base colour meets EN ISO 20471 standards
- Personalisation does not reduce the required fluorescent area
- Printing inks or embroidery threads do not interfere with reflectivity
Personalised hi vis remains compliant as long as modifications stay clear of reflective tape and required coverage zones.
Common Problems People Face When Choosing a Colour
Workers often ask questions like:
“Why does my yellow vest look faded?”
Fluorescent dyes deteriorate under UV light. When colour fades, the garment may no longer comply.
“Is orange better than yellow?”
Neither is “better” it depends on environmental contrast and job regulations.
“Can I mix colours for different roles?”
Yes, but each must still meet EN ISO 20471. Colour consistency also helps supervisors identify roles quickly.
“Why do some companies avoid red?”
It is less common and may blend into certain environments, but it is fully compliant when manufactured correctly.
FAQs
Is yellow or orange more visible?
Visibility depends on contrast with the surroundings. Yellow stands out in most daylight settings, while orange is brighter against road surfaces and construction machinery.
Do colour codes affect night-time visibility?
At night, reflective tape matters more than colour, but fluorescent fabric still improves dusk and dawn visibility.
Can personalised hi vis reduce compliance?
Only if printing or embroidery covers reflective areas or reduces fluorescent coverage.
Is red hi vis legal in the UK?
Yes, red is EN ISO 20471-approved and legal as long as the garment meets the standard.
Conclusion
Hi vis colour codes help workers stay seen, stay safe, and stay compliant with UK law. Knowing when to choose yellow, orange, or red ensures your gear is fit for purpose and suitable for your job’s visibility risks. Whether you’re selecting everyday wear or exploring personalisation options, colour plays a major role in visibility and safety.
For compliant, comfortable, and well-designed high-visibility clothing, explore the collection at Brook Hi Vis.
