How to use primary colors in mobile app design?

Question

Android

There are websites with color palettes like colorhunt.co .
How to correctly determine which elements should be which color?
Using the example of color schemes from the site above, I will describe the colors like this: 1st color is the largest, 2nd is the second largest, etc.

Are there any general rules for determining, for example like this. "1st color is for text, 2nd color for general background..." ?

Answer 1

Can. Search by keyword - app theme. Big topic - see here