You can customize caption settings on your Android mobile device and set your preferred size and color choices. Here's how you can do that:
1. Open the Tubi app
2. Tap on the Account tab at the bottom of the screen
3. Tap on Captions
4. This will take you to your phone's Custom Captions settings. Here, you can adjust things like size, color, and background color.
5. After you've chosen the size and color you'd like, return to the Tubi app your caption choices should now display when you watch a movie or show with captions.