What are the guidelines on when to use `Surface` vs `Background` color in Material 3 design?

Question

I have an app with bottom navigation bar that contains different screens the user can select. It is not clear whether i should use Surface or Background color in Material 3 colors as the default canvas for the screen.

I also have a log in screen and registration and don't know if i should use the same color in the "background" as the above sheets.

Does anyone have any advice or rule of thumbs i can follow to decide when to use Surface and when to use Background color?

Answer 1

After further reading the Material 3 guidelines, it mentions:

Note: Background is a legacy color role. It is recommended to use Surface instead of Background..

Hence the guidelines prefer to use Surface.

Answer 2

As per guidelines for Android Wear:

• Surface colors map to components such as cards, sheets, and menus
• Background color is found behind scrollable content