Android Material Design - How to change background color of Toolbar after CollapsingToolbarLayout is collapsed

Question

After the user scrolls down the screen, the image in the CollapsingToolbarLayout disappears and is left with a toolbar with the back button, content title,

Answer 1

    Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
            R.drawable.header);

    Palette.from(bitmap).generate(new Palette.PaletteAsyncListener() {
        @SuppressWarnings("ResourceType")

        @Override
        public void onGenerated(Palette palette) {
            Palette.Swatch vibrant =
                    palette.getVibrantSwatch();

            if (vibrant != null) {

                collapsingToolbar.setBackgroundColor(getResources().getColor(R.color.cpb_blue));
                collapsingToolbar.setStatusBarScrimColor(getResources().getColor(R.color.cpb_blue));
                collapsingToolbar.setContentScrimColor(getResources().getColor(R.color.cpb_blue));

            }
        }

    });