Swipe ViewPager Tabs - align, change color of icon, return to page 0 and shrink toolbar

Hello, I made in the code below a ViewPager with Tabs: In the Main code:

private TabLayout tabLayout;
private ViewPager viewPager;
SwipeRefreshLayout refresh;
ParseUser currentUser;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    getSupportActionBar().setDisplayHomeAsUpEnabled(false);


    viewPager = (ViewPager) findViewById(R.id.container);
    setupViewPager(viewPager);

    tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(viewPager);

    tabLayout.getTabAt(0).setIcon(tabIcons[0]);
    tabLayout.getTabAt(1).setIcon(tabIcons[1]);
    tabLayout.getTabAt(2).setIcon(tabIcons[2]);
}

final int[] tabIcons = new int[]{
        R.drawable.mainazul,
        R.drawable.lupaazul,
        R.drawable.menuazul
};

private void setupTabIcons() {

}

private void setupViewPager(ViewPager viewPager) {
    ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
    adapter.addFragment(new FragmentoMain());
    adapter.addFragment(new PesquisaFrag());
    adapter.addFragment(new Menu());
    viewPager.setAdapter(adapter);
}

class ViewPagerAdapter extends FragmentPagerAdapter {
    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager manager) {
        super(manager);
    }
    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }
    @Override
    public int getCount() {
        return mFragmentList.size();
    }
    public void addFragment(Fragment fragment) {
        mFragmentList.add(fragment);

    }

    @Override
    public CharSequence getPageTitle(int position) {
        return null;
    }}

In my xml:

<android.support.design.widget.AppBarLayout
    android:id="@+id/appbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"

    android:theme="@style/AppTheme.AppBarOverlay">



    <android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        app:tabMode="fixed"
        android:background="@color/branca"
        android:layout_height="40dp"
        android:layout_gravity="bottom|fill_vertical"
        android:fillViewport="true" />

</android.support.design.widget.AppBarLayout>

<android.support.v4.view.ViewPager
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />

Tabs are only with icons, without text.

It's working fine, but I have the following questions:

2. The icons are always the same color. You can change them as the page is selected.

Thank you.