Dark mode is coming to Gmail. Google tweeted a Star Wars_-_themed message on Tuesday announcing dark theme for Gmail on Android and iOS. Star Wars because "dark," obviously.
According to the Google Suite blog, dark theme has already begun rolling out.
Here's how to enable dark theme:
In your Android Display system setting, set your device to Dark theme. Gmail will automatically respect the system default setting. On Pixel, when Battery Saver is enabled, Gmail will default to Dark theme automatically. In Gmail go to Settings > Theme and select "Dark".
Enable Dark theme for iOS 11 or 12 by going to Settings > Dark Theme. To enable dark theme on iOS 13, either set your device to dark theme in iOS Settings, and by default, Gmail will automatically respect the system default setting, or in Gmail go to Settings > Theme and select "Dark".