• Use Device theme-YouTube will follow the system-wide settings selected by the user.
• Light theme-traditional white background with dark text.
• Dark theme-black or dark gray background with white text.

This makes it easy for Android 10 users who switch often between Light and Dark theme but don’t like the way the latter looks on a certain app. Other Google apps also have added this trio of options on Android 10 even though they already had a Dark theme toggle.

For those unfamiliar with Dark theme, it is simply a way to protect the eyes of a smartphone user (and bystanders) in a dark room or at night. The bright white background can strain eyes and make it uncomfortable for others nearby. In addition, there are simply some smartphone users who like the look of Dark theme. Apple also added a native Dark theme setting with last month’s release of iOS 13.

Those with Android 9 or older will have to live with having the single Dark theme toggle on their YouTube app.