Colors make a difference to our environment. They help us analyze the surroundings and distinguish between objects. We recognize plants as green and the sky as blue, whereas a frog, for example, can be either green or blue. Deviant colors, in this case blue, warns us about poisonousness. If we detect unusual colors in our food, for example, we associate them with rottenness, which then activates a warning in our mind “Don’t eat!” Colors cause diverse feelings and opinions, and even distinct cultures see them inversely. In Argentina and China, for example, the color red is considered to bring luck, whereas in Germany and Nigeria it represents the opposite. Colors in country flags are also representative of certain characteristics, usually referring to the history, people and the wealth of the country.

Colors of the rainbowColor psychology has been of particular interest to marketers as it helps to understand how different colors are perceived by consumers and the kind of values they bring across. Brands use colors in their logos and websites to visualize their brand values. For example, red in a logo implies boldness and dynamism, whereas green is usually used to reflect nature, sustainability and harmony.

In safety, certain colors create an appropriate response or catch our attention- and what is more important in workplace safety than paying attention? Therefore, the colors used for safety signs and symbols have been chosen for a reason.

Contrasting colors are used to direct readers’ attention to a particular concept or a standout call-to-action. Imagine reading plain black text on a white background - it becomes challenging to spot relevant information, doesn’t it? This same logic can be applied for safety signs; safety sign colors are used to direct people’s attention towards essential information. If safety signs blended into the background, they would go unnoticed – with potentially detrimental effects.

It is interesting then that despite cultural differences such as China vs. Germany on red, safety signs are largely standardized in their coloring. ISO has standardized the colors and basic shapes of safety signs making them easily recognizable throughout the world. OSHA has also created guidance on approved safety sign formats. Since the introduction of safety signs and signals regulation in 1992, fatal injuries have decreased by 50%.

Having regulated safety signs helps to overcome the issue of language barriers and local regulations, which is why the standardization of the signs is widely seen as a good thing. Safety signs create this kind of universal language, if you like, that uses our visual recognition and familiarity with the colors, shapes and images as its words.

Although the main goal of safety signs is to catch our attention, colors have a more significant role than that. Let’s have a look at the psychology and standards behind four common safety sign colors.

Safety sign colors

Red, yellow/amber, green and blue: these are the most frequently recognized colors in safety, excluding black and white. What do these colors represent, and in what kind of signs are they used?

Color Red in SafetyRed

Out of the four colors, red is the most noticeable. It stands out and is quickly registered by our brains. According to June McLeod, a Color Psychology Consultant, the color red is extremely powerful: "It takes 2/100ths of a second to register red yet 25/100ths of a second to register 3 words of a text."

Red is quick to catch the eye and, like many safety sign colors, transcends the barriers of language. Imagine being in a foreign country and not understanding the local language. You, however, know what a red safety sign stands for – for the layman, that probably means “hey, this area is risky, so be careful or avoid it entirely.” Therefore, despite not understanding the written message on the sign, you still recognize the warning. It is exactly this ability to catch our attention that explains why red is generally used for signs that communicate danger, prohibition or alert in almost all of the world.


Safety Sign - High VoltageThe color yellow is also very noticeable for the human eye, and like in country flags, it tends to be associated with optimism and joy. Our brain is easily drawn to yellow, which is why it’s used in safety signs to highlight instruction and to provide important information.

You can often see a free-standing yellow sign instructing people to be aware of the slippery floor, for example. Another common sign is a yellow triangle with a black frame and a lightning strike in the middle warning about high voltage. Yellow is often used with black, a contrasting color, and especially a triangular sign with black outline is a common sight.

Green Exit SignGreen

Green is a positive color seen to mirror positive energy, balance, harmony, health and nature. In safety signs, green juxtaposed with white is used to signify emergency exits, first aid and safety equipment. Pharmacies use green cross signs to help people locate them. Hence, green is often associated with the message “no danger”.

Moreover, we also associate green with the permission to “GO”. Traffic lights bestTraffic Lights demonstrate our reaction to the colors green, amber and red: amber standing for “Get Ready” and red telling us to “STOP”. No, amber does not mean speed up, despite what some cheeky road users think!


Blue is the color of the sky and the sea. It is usually considered mentally soothing and represents peace. In a company logo, blue is associated with trust and dependability, and is one of the most popular colors in branding – which might have something to do with the fact that it is the favorite color of both males and females.

In safety, blue indicates mandatory orders and safety information, such as “safety equipment must be worn” or “parking prohibited in front of the fire exit”. Choosing blue for such orders could be influenced by the connotations of trust and authority that are attached to the color.Safety Sign - PPE

It is clear then that color psychology helps us understand how our brain processes and reacts to different colors. The way in which these colors are generally perceived outside of safety have certainly had an influence on their usage in safety signs. The fact that the colors are standardized has also created a pattern in our brains that recognizes these colors and associates them with a certain message, no matter the country.

Color is not the only characteristic of safety signs. There are many regulations that aim to standardize their appearance on an international scale.

Safety sign standards

When choosing safety signs for your workplace, you must check which safety signs comply with your local regulations.
The Health and Safety Executive (HSE), the regulatory body for Health and Safety At Work in the UK, has set rules for safety signs and signals. These regulations state the shape, size, color and material to be used. Here is a table showing how HSE classifies the meaning and usage of each of the abovementioned colors:

Safety Sign Colors [table “” not found /]<br />
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In the USA, corresponding standards are issued by the regulatory body of OSHA (Occupational Safety and Health Administration). ISO (the International Organization for Standardization) has also set standards for safety signs, which applie throughout the world. ISO 7010, for example, regulates safety sign standards across Europe. In 2013, ISO 7010 became a European Normative (EN) and it was adopted by the European Law. The symbols regulated by ISO 7010 don’t include any written language making them readable for anyone, despite their native language, level of literacy and age. For safety sign colors, the standard refers to ISO 3864.

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What do I need to know when choosing safety signs?

When choosing safety signs for your workplace, you must check the local and national standards for compliance. As well as being of particular size, shape and color, signs must also be located in the right spot. If you have internationally diverse staff, it is advisable that the language in the signs is familiar to everyone. It is also helpful to advise the staff on the safety signs and their meaning, especially if they differ from the international standards.

Finally, it would be interesting to hear if any of our readers have spotted or heard of countries that have different safety signs from the ones mentioned in this post. You can email me at or send a message via social media.

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A Copenhagen Business School graduate with a MA in International Business Communication, Tytti joined the Pro-Sapien marketing department in 2017 and brings a wide range of experience to the team – not to mention the ability to fluently speak three languages, Finnish (native), English and Spanish. Outside of business Tytti is an avid gymnast having competed at international level in the Aesthetic Group Gymnastics Championships, and has lived in Finland, France, Argentina, Spain, Denmark and now the United Kingdom. As the Graduate Marketing Executive Tytti coordinates Pro-Sapien’s social outreach and blog content, and can be reached at


  • Doe it matter if the round shapes change to square shapes but information stay the same according to the regulations.

  • Thank you for your interest in the article. Your question is very relevant. The regulations for safety signs describe the geometric shape and color of the signs. So to answer your question, yes it does matter what shape the sign is. Even if you keep the same information and colours stated in the regulations, the shape will matter. For more information on safety signs you can see this link to Health and Safety Executive’s (HSE) the Health and Safety (Safety Signs and Signals) Regulations 1996:

  • Good definitions. Safety signs are very important especially in construction places. It can help to avoid accidents and can also be life saver.

  • Thank you Sunil for reading this article. I find that the importance of safety signs (especially the visual aspect) has increased due to the increasingly global and mobile workforce. The more we standardize the design of the signs, the better they’ll be understood across countries.

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