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Why Red and Blue Are Primary Emergency Colors

Why Red and Blue Are Primary Emergency Colors

At LedEquipped, we’re proud to provide first responders in several different areas with emergency light bars and other LED products that make them as recognizable as possible. Our goal is to ensure both safety and efficiency when first responders are rushing to a location, and we have numerous options available to help here.

We get a fairly common question from some of our more amateur customers: Why are police lights red and blue in the first place? The answer here lies partially in the history, and partially in practical theory. Let’s take a look.


Back in the 1940’s, most police departments used just a single beacon light mounted atop patrol units. They may have also used a non-flashing red light at the front of the car.

Red may have been the original choice here due to the way it’s associated with “stop” and other warning signs. Over time, and as technology made them available, emergency vehicles began to incorporate flashing lights into their schemes, as well as blue lights. Why the combo of red and blue?

Light Theories

It’s tough to narrow down exactly why this combination became the go-to choice – regulations are different from state to state. One theory is that while red alerts drivers, it can also be overlooked in traffic since most vehicles have red tail lights – thus including blue. Other studies indicate that red lights are more visible during the daylight, while blue lights are more visible at night, so the combination covers all bases.

Some experts also claim that using both colors decreases issues with drivers who are colorblind. Those who struggled to see red can usually easily see blue, and vice versa. Red has the longest wavelength as well, meaning it will disperse less and can more easily reach the eye through foggy conditions.

Quick Access and Modern Lighting

Police and other emergency vehicles need to gain access to incidents as fast as possible, and good lighting is a big factor. In the early 1990’s, advances in technology saw a rise in the popularity of emergency light bars, and departments began using LED lights for their efficiency. Today, our LED lights are offered in numerous options, flash patterns and programmable features.

To learn more about the origins of primary emergency light colors, or to find out about any of our services, speak to the pros at LedEquipped today.

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