In recent years, dark mode has emerged as a popular user interface (UI) design trend across various digital platforms, offering users an alternative color scheme that replaces traditional light backgrounds with darker shades. Dark mode not only provides a stylish and modern aesthetic but also offers functional benefits such as reducing eye strain in low-light environments and extending battery life on OLED screens. This article explores the principles, benefits, and best practices for designing in dark mode to enhance user experience and meet the growing demand for this feature in mobile and web applications.