Color Associations by John Hua.

User Interface (UI) and User Experience (UX) design are the backbone of modern digital products. From mobile apps to websites to enterprise dashboards, thoughtful design determines how users interact, engage, and ultimately feel about technology. While functionality is essential, aesthetics often define whether a product feels intuitive or frustrating. At the heart of design thinking lies a crucial question: how should colors be used to communicate, persuade, and delight users?

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Login screen UI/UX color usage comparison. By John Hua.

Colors are not merely decorative. They influence perception, guide attention, and evoke emotional responses. Designers make color decisions at the intersection of psychology, accessibility, branding, and usability. This essay explores how designers approach UI/UX and color choices, considering both theoretical frameworks and practical applications.

Before diving into color decisions, it is important to distinguish between UI and UX.