What Is Color Theory? Meaning & Fundamentals

Illustration by Ran Liu

Color is one of the most powerful tools for visual communication. It can influence our emotions, our mood, and our behavior. That’s why it’s so important for product designers to select colors carefully.

In this article, we’ll explore the basics of color theory for designers and provide information to help you design effective and visually interesting color schemes.

What is color theory?

Color is an essential part of human-computer interaction, and similar to other elements like typography, designers should select colors with care. Color scheme is a term that designers use to describe color combinations that they use in GUI design . Since there are infinite color combinations out there, it can be hard to decide what color scheme will work the best for your product. Fortunately, we have color theory, a discipline that helps us select balanced and effective color combinations.

Here are a few practical recommendations from color theory that will help you select powerful color combinations for your design system.

Limit the total number of colors

Achieving harmony in color combinations is one of the main color theory principles. When you create a new scheme, it might be tempting to add dozens of colors to it. But it’s better to avoid that temptation. Why? Because it’s really hard to achieve a visual balance when you use too many colors. You can also easily overwhelm your users.

So how do you avoid this? Keep your color scheme simple, with a maximum of two or three colors. Some designers think that two or three colors will limit their creativity, but that’s not true. It’s possible to create interesting visual combinations by playing with shades and tints of those colors. Simple schemes also work best for your users.

Example of a color scheme created with just one red color. Image credit Adobe.

Use the color wheel to select colors

The next step is to understand how to select the actual colors. Designers typically rely on the color wheel to solve this. The color wheel includes primary colors (red, yellow, blue), secondary colors (a mixture of primary colors; orange, green, and purple), and tertiary colors (colors created by mixing equal parts of one primary color and one secondary color; citron, russet, buff).

The 12-spoke color wheel. Image credit Sakurambo.

Primary, secondary, tertiary, and quaternary colors. Image credit KetanNaik.

Here are three popular types of color schemes that you can create with a color wheel:

Monochromatic. Monochromatic schemes use a single color, but with variations of tints, shades, and tones of the color. This scheme is very easy on the eyes; since the colors naturally go well together, they create a soothing effect.

Example of monochromatic color scheme. Image credit Adobe.

Analogous. Analogous color schemes use a few related colors—one color is the dominant color, while others support it. The supportive colors enrich the scheme and make it more visually appealing.

Example of analogous scheme created from three colors that are close to each other on the color wheel. Image credit Adobe.

Complementary. In their most basic form, complementary schemes consist of only two contrasting colors (for example, a dominant green color and an accent red color). This scheme works well if you want to attract attention.

Example of complementary color scheme. Image credit Adobe.

Adobe Color is an excellent tool for creating color schemes, because it gives you the freedom to modify existing schemes. Every color on the palette can be individually modified with a few simple clicks.

Example of creating a monochromatic scheme using Adobe Color. Image credit Adobe Color.

Understand the psychology of color

Focusing on the psychological aspects of color is an essential part of understanding color theory. When you select a UX color palette for your product, you’ll usually think about how things will look, but it’s equally important to think about how they feel, too. Color has a powerful psychological influence on the human brain, with each color representing different meanings and emotions for your users.

While there are no universally acceptable meanings, here are some general feelings that colors evoke for most people:

Red: danger, importance, love. Red is known as the color of energy—simply looking at it can increase a person’s pulse, heart rate, and metabolism. It’s an excellent color for grabbing a visitor’s attention; try using it to highlight the most important elements on your page.
Orange: energy, optimism, fun. Orange has a positive energetic vibe. It’s also associated with inexpensive products, making it a good color for e-commerce stores if you want to highlight the best price.
Yellow: happiness, attention, warmth. Yellow denotes a sunny disposition; when combined with black, it will quickly command attention. (Think about yellow cabs in NYC, for example.)
Green: growth, success, nature. Green is fantastic for products that are close to nature. It’s also a popular color to use within user interfaces, giving users a signal that an operation completed successfully.
Blue: trust, comfort, calmness. Blue represents relaxation and comfort. Brands love this color because it gives customers an impression of inner security.
Purple: luxury, creativity, wisdom. Purple is usually linked to royalty as well as luxury products.
Black: power, sophistication, mystery. Most brands limit black to text and accents. As a primary color, black may be prominent on fashion websites to convey a feeling of luxury.
White: cleanliness, health, innocence. White usually makes us think of health and cleanliness. Designers typically choose this color to suggest a product’s safety, especially for medical equipment and high-tech products.

Gender and color

Does gender play into color preferences? In one study, researcher Joe Hallock did find some big differences.

Study results of men’s and women’s most and least favorite colors. Image credit Smart Insights.

Below is a quick summary of the study:

Blue is the most popular color for men and women alike.
Despite popular belief, pink isn’t a favorite color for women.
Orange, brown, and yellow are the most unpopular colors for both men and women.
Men generally prefer bright, contrasting colors, while women prefer softer colors.

Age and color

Age also plays a role in color preferences. Faber Birren, the author of Color Psychology And Color Therapy, found that young people tend to prefer colors with longer wavelengths (such as red and orange), while older people like colors with shorter wavelengths (such as blue). Joe Hallock’s same study on gender and color preferences confirmed Birren’s findings, but also found that many age groups prefer purple.

Graph of favorite colors by age groups; studies find that young people tend to prefer colors with longer wavelengths (such as red and orange), while older people like colors with shorter wavelengths (such as blue). Image credit Joe Hallock.

Practical tips for using color

Now that we know what color theory is, it’s time to explore some practical tips for using colors in UI design.

Use mood boards to find the right colors

Mood boards are collections of visual inspiration. Mood boards can be very useful for selecting almost any visual design decision, including color. If you find an image or photograph that you like, you can use a tool like Coolors to create a color scheme right from it.

Example of a mood board. Image credit Designmodo.

Create focal points using color

Good scannability is essential for web design. Visitors should be able to find the information they need at a glance. The colors you use can support this, as they can help guide the user’s eye. For example, you can use a contrasting color for a call-to-action button to give it more visual weight and, thus, make it more prominent.

Decide when and how to use vibrant and soft colors

Most colors will fall into one of two categories: vibrant or soft. Depending on the nature of your project, you can rely more on the first or second group.

Vibrant colors are colors that stand out from the background and pulse with energy. These colors are great for creating an energetic vibe and are a good choice for companies that want to present themselves in a non-traditional manner.

A vibrant homepage, colored in pink and blue, creates an energetic atmosphere. Image credit Vredestein New Horizons.

Soft colors, on the other hand, blend in with the design and help convey a sense of calm that helps users feel at ease.

Product collection pages using soft pastel and earthy color schemes. Image credit Collagerie.

Ultimately, you should base your color selection on what you want your customers to feel when they interact with your product.

Don’t forget about accessibility

Design is not only about aesthetics; it’s also about functionality and usability. When designing UI, it should be accessible to people with various abilities. One particular challenge that designers face when they work with colors is considering how people with color blindness or color vision deficiency (CVD) will interact with the product.

These color wheels show how color looks for those with normal vision (far left), and the same colors as seen by those with a red-green color deficiency (middle and right). Image adapted from Sakurambo.

Here are two things to remember when designing with color:

Never use color alone to communicate the meaning. Use multiple visual cues to communicate essential states in your product. For example, when you show an error message, don’t use red alongside text that says “Required fields are in red.” Instead, add a visible sign (such as an asterisk) and say, “Required fields are in red and marked with an *.”

Some visually impaired users can’t see red or green characters, so avoid using these colors alone to convey information. Image credit WebAIM.

Avoid low contrast text. Placing two colors with low-value contrast next to each other can make your copy very difficult to read. The Web Content Accessibility Guidelines (WCAG) recommend that the background-to-text contrast ratio is at least 4.5:1. Keep this in mind that when you design text as well as functional elements, such as buttons.

Low-contrast text can be difficult to read, leading to a poor user experience. Image credit Nick Babich.

When it comes to accessibility tools, we recommend using Color Contrast Checker and the NoCoffee vision simulator for Chrome. The first tool will help you check your color combinations according to WCAG guidelines, while the second tool allows you to experience color blindness yourself while designing.

Using a tool like NoCoffee shows you how users with protanopia—those who can’t differentiate the colors red and green—see different websites. Image adapted from CNN.

Conclusion

Color is just one of the tools that designers love to play with. At the same time, it’s one of the tools that can be tricky to master. The rules mentioned above will set a good foundation for visual designers, but the only way to improve is to master the skill of creating great color combinations. Practice makes perfect.