Colors are massive part of our environment, helping us analyze surroundings and distinguish objects. We know plants are green and the sky is blue.

In safety, certain colors catch our attention, therefore safety sign colors are chosen for a reason.

Contrasting colors grab readers’ attention. Safety sign colors direct people’s attention towards essential information. Unnoticeable safety signs yield dangerous results.

ISO standardized the colors and basic shapes of safety signs, making them recognizable worldwide. OSHA also created guidance on approved safety sign formats. Since the introduction of safety signs and signals regulation in 1992, fatal injuries decreased by 50%.

Universal safety signs overcome language barriers and local regulations. Safety signs catch attention, with colors playing a significant role. Let’s look at four common safety sign colors and the psychology behind them.

Download FREE health and safety icons pack »

Safety sign colors


As a very distinctive color, red stands out. June McLeod, Color Psychology Consultant, said: "It takes 2/100ths of a second to register red, yet 25/100ths of a second to register 3 words of a text."
red safety

Red transcends language barriers. You're not fluent in every language, but you know what a red safety sign stands for: “hey, this area is risky. Use caution or avoid it entirely.” If you do not understand the writing on the sign, you understand the warning. Red catches our attention, explaining why it communicates danger and caution.


high voltage

Yellow is another distinct color. Humans draw to yellow, thus it instructs and provides important information.

For example, free-standing yellow signs warn about slippery floors. The yellow triangle with a black frame and a lightning strike is a common sign. Yellow couples with black, a contrasting color.


green exit

Green mirrors positive energy, harmony and nature. In safety signs, green juxtaposed with white signifies emergency exits, first aid and safety equipment. Hence, we associate green and “no danger”.

Moreover, we associate green with permission to “GO”. Traffic lights demonstrate our reaction to green, amber and red.


Safety Sign - PPE

Blue is considered mentally soothing and represents peace. In a company logo, blue is associated with trust and dependability. In fact, blue is a popular branding color, think Facebook, Twitter and LinkedIn logos. Color psychology helps us understand how our brain processes different colors. Blue, for instance, connects with trust and authority.

In safety, blue indicates mandatory orders and safety information. For example, “safety equipment must be worn” or “parking prohibited in front of the fire exit”.

However, color is just one safety sign characteristic.

Safety sign standards

When choosing workplace safety signs, check your local regulations. Many regulations standardize safety signs' worldwide appearance. In the UK,
The Health and Safety Executive (HSE) set rules for safety signs and signals, stating shape, size, color and material. The below table shows HSE's color definitions:

Safety Sign Colors [table]

In the USA, OSHA issues corresponding standards. On the other hand, ISO sets worldwide safety sign standards. For example, ISO 7010 regulates safety sign standards across Europe, adopted by EU law in 2013.  ISO 7010 regulated symbols are accessible regardless of native language, literacy level and age. For safety sign colors, refer to ISO 3864.

How should I choose safety signs?

It's important to follow the regulations dedicated to safety sign colors and shapes. Arguably, safety sign location is equally important - signs are useless if not seen.

Finally, signs must be understood by all. Issue staff training on safety signs, especially if they differ from the international standards.

Free Safety Icons Pack Icons to make safety training more visual


  • 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.

  • Good post on warning signs. Electrical signs are much better because they are brighter. Was good to read about safety signs post because we are in this field and was very useful.

  • Thanks for reading, Sunil! I’m pleased to hear you found the article useful. It sure was an interesting topic for the team here to research.

Leave a Reply