Color is like everything else, it’s best used in moderation. You will tend to get better results if you stick to max three primary colors in your color scheme. Applying color to a design project has a lot to do with balance and the more colors you use, the more complicated it is to achieve balance.
Structuring colors is one of the things that all designers should do when they work with UI. If you don’t structure colors, you can find overwhelmed by how many colors you use by the time you reach the end of the design project.
Colors can speak in ways that are every bit as powerful as language. They can reflect the personality of your brand. They can attract users, and they can better communicate your message. Any UI design guidelines are likely to mention colors prominently.
Zander Whitehurst has come up with a handy list of color rules every UI designer should know. He advises categorizing your color palette into the brand, functional, feedback, accent, and neutral colors.
1. Brand Colors
A brand’s logo has the ability to drive purchasing decisions and increase its recognition. Color even triggers certain emotions in people. You should have a single brand color that users immediately associate with your product. The button is a great component of a brand color.
The psychology of color for logo making can help your business establish trust and familiarity by eliciting the right emotions. It’s no surprise that the most popular brands in the world have a strong association with their logos.

2. Functional Colors
Functional colors make up the architecture of your interface. Typically used as across navigation, tables, modals, dialogs, text, links, and states. As well as components, functional colors are used within type from headings to links.

3. Feedback Colors
Most systems reserve a certain red for errors, green for success, yellow for warning, and (possibly a lighter sky) blue for informational messages. Feedback color is critical because it’s positioned at the top of the page interacting with other key components and/or encountered as a result of an unwelcome circumstance.
Feedback colors are used to indicate the state of an action. In other words, they give users feedback. Typical feedback states are a success, warning, info, and danger, but you have primary and secondary versions of these.

4. Accent Colors
Accent colors are those colors that are used for emphasizing a color scheme. These colors can often be bold or vivid. They are used sparingly, only to either emphasize, contrast, or create rhythm. More toned down colors like neutrals or darker shades can also be used depending on the surroundings.

5. Neutral Colors
Neutral colors are most clearly defined as hues that appear to be without color, and that don’t typically appear on the color wheel. Neutral colors, therefore, do not compete with primary and secondary colors and instead compliment them.

6. Interaction Colors
Interactions like hover and active states are usually forgotten about until the build phase of a UI. Choose your interaction color with a % layer of neutral colors in your design system symbols.

7. Contrast
Contrast is one of the key factors influencing the scannability and visual hierarchy of the page. It enables the designer to present the layout in a way that informs users which points of interaction are vital and which ones are secondary.
Color contrast is also a practical method of color in UI design. Contrast can evoke a various emotional responses from users. Colors on opposite sides of the color wheel can generate the strongest contrast, like black and white.

8. Color Blindness
About 4% of the population has some form of color blindness. One in 12 men and 1 in 200 women are color blind and face challenges with a lot of online products like websites, apps, games, and webshops in their daily life.
Color blindness is an inherited condition that limits a person’s ability to distinguish between color shades, most commonly reds and greens. Our ability or inability to recognize color is dependent on cells in our eyes called cones.

Conclusion
While the color theory is a complex subject, it isn’t particularly complicated to learn the basics. From there, designers can build on their knowledge to create more varied and sophisticated color palettes for their designs.
A well-designed color palette, particularly one that includes some unexpected hues, isn’t merely an aesthetic choice. It can have significant psychological effects on users, which UX designers should capitalize on in order to create better experiences.
You can see more other articles color: 15 Best Color Tools for Designers