What is dark mode? Definition and design considerations

Dark mode is a color scheme that uses light text on dark backgrounds — typically opt-in or automatic based on operating-system preference, and a second design surface most products now support.

The pattern is no longer optional. A material share of users sets dark mode at the OS level and expects every app to follow. A product that ships only a light theme reads as old-fashioned and, in low-light conditions, often physically uncomfortable to use.

What QA misses in dark mode

The usual culprits are hardcoded colors and images that assumed a white page. A button that defines its own color: #000 instead of inheriting from the theme stays black on the dark background. A logo with a transparent background and dark strokes disappears against the dark surface.

A design QA pass that walks the product in both light and dark mode catches most of these before they ship. Capture each affected screen in both themes and ship the comparison; the engineer can see exactly what to fix without re-testing the rest of the surface.