A good color mastery in Interface Design (UI) is crucial. It can improve usability and also help to influence the perceptions a user may have, like strengthening brand recognition and generating more conversion.

Harmony

Color is one of the most powerful tools in a designer's arsenal. Finding a killer color combination can create harmony and level up the overall experience considerably.

In this example, we see a unique combination of blue and bright cyan highlights.
In this example, we see a unique combination of blue and bright cyan highlights. Its out-of-the-box thinking creates a stunning color harmony.

Contrast

Color contrast gives dynamism to the interface. You can create high contrast by using complementary colors. These are colors that face each other in the color wheel.

This website demonstrates a high contrast by combining a black background with bold colors.
This website demonstrates a high contrast by combining a black background with bold colors. In this case, red is complemented by a unique green tint.

Interaction

The characteristics of interaction elements, for instance, the color, must be used consistently throughout the interface. For example, calls to action need enough contrast so that the user can identify them quickly.

Here we see some pinks and reds with a clear blue call to action button.
Here we see some pinks and reds with a clear blue call to action button, creating plenty of visual interest and drawing attention to itself instantly.