Why Firetrucks are Red – And More on the Psychology of Color

November 8, 2017

How people react to colors like blue, green, yellow, red and black.

Studies show the most visible color to the human eye under any lighting condition is a greenish-yellow (think the color of a tennis ball). Hence, if you really wanted to catch someone’s eye – like, say, you are painting a firetruck you are hoping people see barreling down the street – you’d use a greenish-yellow color.

So why aren’t firetrucks painted greenish-yellow?

Well, for a period of time across a variety of cities, they were. And morale suffered.

Why? It comes down to the psychology of colors. Thanks to evolution, we have subconscious reactions to certain colors.

Let’s go back to the firetruck example. Greenish-yellow is the most-eye catching color, which is good for fire trucks. But it’s also a color we subconsciously associate with cowardice. When trucks were painted that greenish-yellow, the morale of firefighters dropped.

Conversely, red is a color we subconsciously associate with bravery and courage. After a while, firetrucks were again painted red in many cities, and morale jumped back up.

"They're real proud to have red again," one California fire chief said when the department started buying red trucks, instead of greenish-yellow ones. “A lot of people will laugh at that, but I'm not making this up."

The point? When designing a website, picking a logo, painting a store, etc. you need to pick a color that matches the vibe you are trying to give off. But what are the vibes certain colors give off, subconsciously?

In the LinkedIn Learning course Universal Principles of Design, Instructors William Lidwell and Jill Butler taught courses on our subconscious reactions to a variety of colors. Here are a few of their lessons:

Green: The most inviting color, even if we don’t look particularly good in it.

What green conveys: Think about our ancestors. Green literally means go – go toward the lush greenery as there is generally food and water there. For that reason, green is a particularly inviting color. It also reduces our anxiety, frees our mind and helps us focus.

What it’s good for: Any brand or product trying to convey a natural image, as well as obviously a product that’s literally “green” – i.e. environmentally friendly. It’s also a sign of safe passage, so a green button on a website, for example, will signal to people it's safe to click.

Green also reduces anxiety. For instance, it makes sense to paint a dentist’s office green, as it’ll reduce the anxiety of the patients.

What it’s bad for: A person in green is rated less attractive than someone in any other color, except yellow. That’s because green skin usually means a person is sick, and green clothes mimic that.  

Blue: Great for collaboration and inspiration, bad for food.

What blue conveys: Blue, like green, is an inviting color that inspires good feelings. Again, think about our ancestors: blue is the color of water, something we all need to live. We are attracted to it.

Blue, also like green, inspires creative thinking and decrease anxiety. We also associate it with friendliness and peacefulness.

What it’s good for: Blue is a highly popular color that conveys friendliness and inspiration. So, it’s perfect for aspirational brands, like a nonprofit or a purpose-driven company (like, say, LinkedIn). It’s also smart to accent blue in spaces you want to increase collaboration, like an office space or a classroom.

What it’s bad for: Blue is not a good color for food, as darker colors like blue and black are associated with rotten, spoiled food. Also, blue isn’t particularly attention grabbing, and is awful for warning labels and other avoidance messages.  

Black: The bad boy color that's perfect for high-end products.

What black conveys: As you might expect, black is associated with evil and foreboding and conveys aggression and dominance. For example, black dogs have been proven to be harder to adopt than lighter-colored ones, as people think they are more aggressive. Studies also show that sports teams with black uniforms are penalized at a higher rate than teams in lighter-colored uniforms.

What it’s good for: Interestingly, black, glossy products are perceived to be classy and timeless (think chic black leather shoes or a black briefcase). Adding black can actually make a product feel more valuable.

What it’s bad for: Obviously, if your intention is to convey a warm, cuddly feeling or a more aspirational organization, black wouldn't work well. Also, if value is a key part of your branding, than lighter colors work better than black.

Looking to learn more about design? Watch the full LinkedIn Learning course, Universal Principles of Design, today.