Set theme color dynamically

Question

I am using themes (dynamically) in my android app, like this:

my_layout.xml (extract):

Answer 1

What about passing theme id via Intent?

Intent intent = new Intent(activity, MyActivity.class);
intent.putExtra("theme", R.style.MainTheme_Green);
activity.startActivity(intent);

And then in onCreate:

// assuming that MainTheme_Blue is default theme
setTheme(getIntent().getIntExtra("theme", R.style.MainTheme_Blue));