Microsoft Launcher 5.10 version released on Android to users enrolled in the beta program. This is a small update that adds support for setting the dark theme in Android 9 Pie and Android 10. Microsoft Launcher already offers support for the dark theme but had to be chosen manually, while the new option automatically adjusts it based on system settings. However, it remains the option to set a different theme from the system setting, an option if you want to use the transparent theme.
The system-wide dark mode was only added in Android 10, however Android 9 Pie presented an option for a dark theme that only affected some Google apps like Phone, Messages, and Contacts. Otherwise, this version only includes performance improvements and bug fixes.
If you wish to try out new features in development for Microsoft Launcher, you can sign up for the Beta program here and download the app from the Play Store.