The DayNight Solution

Google’s preferred solution is for you to use a theme that adapts based upon whether the device is in dark mode or not. That way, you can have a light theme “normally” while having a dark theme in dark mode.

In particular, AppCompat supports this via its DayNight theme family. The basic recipe is:

• Change your theme’s parent theme to Theme.AppCompat.DayNight (or to some other theme that extends Theme.AppCompat.DayNight).
• Define alternative colors, icons, and other resources in -night resource sets. For example, your regular (“day”) colors might be in res/values/colors.xml, while the “night” colors might be in res/values-night/colors.xml. If you use the same name for the individual resources (e.g., primary), Android will choose the proper value to use depending on whether dark mode is enabled.

You can learn more about the DayNight option in the "Dark Mode" chapter of Elements of Android Q!