A dark theme displays dark surfaces across the majority of a UI. It's designed to be a supplemental mode to default (or light) theme.

Dark themes reduce the luminance emitted by device screens, while still meeting minimum color contrast ratios. They help improve visual ergonomics by reducing eye strain, adjusting brightness to current lighting conditions, and facilitating screen use in dark environments – all while conserving battery power. Devices with OLED screens benefit from the ability to turn off black pixels at any time of day."

Dark theme design is guided by four principles

• Darken with grey
• Color with accents
• Conserve energy
• Enhance accessibility

Which are then further specified by four properties

• Contrast
• Depth
• Desaturation
• Limited color