Dark mode is a setting that alters the colour palette of a website’s interface to enable its contents (text and images) to be viewed using only dark background and light foreground colours in order to enhance the contrast.
Dark mode is also good for the environment, as it allows substantial energy savings to be made: tests on various mobile devices with screen brightness set at 30-50% have shown that the energy saving using dark mode is around 3-9%, which rises exponentially when screen brightness is set at 100%, generating energy savings of 47%.