It will become available to everyone soon.
Google has added to Gmail for Android dark theme. It allows you to comfortably use the application at night, said Chronicle.info with reference to lifehacker.ru.
In the colors of the dark theme is dominated by gray and black colors. The selected mail is displayed in red. Avatar, tags, and other colored elements become more subdued.
The dark theme can be enabled in the General settings. Like other Google applications, Gmail has three options: “Light”, “Dark” and “System”. The last option is relevant to users Android 10: it has a dark theme can be set once for all applications in the OS settings.
To enable the dark theme need Gmail 2019.08.18.267044774. But not the fact that the configuration will appear — you may have to wait.