Default ViewPager

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.Random;

import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.graphics.Color;
import android.support.v13.app.FragmentPagerAdapter;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;


public class MyActivity extends Activity {

    SectionsPagerAdapter mSectionsPagerAdapter;
    ViewPager mViewPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);

        // Create the adapter that will return a fragment for each of the three
        // primary sections of the activity.
        mSectionsPagerAdapter = new SectionsPagerAdapter(getFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);

        mSectionsPagerAdapter.addFragment(PlaceholderFragment.newInstance(4, getResources().getColor(R.color.android_blue)));
        mSectionsPagerAdapter.addFragment(PlaceholderFragment.newInstance(5, getResources().getColor(R.color.android_darkpurple)));
        mSectionsPagerAdapter.addFragment(PlaceholderFragment.newInstance(2, getResources().getColor(R.color.android_orange)));

        mViewPager.setAdapter(mSectionsPagerAdapter);
    }


    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        List<Fragment> fragments; //acá voy a guardar los fragments

        //constructor
        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
            this.fragments = new ArrayList();
        }

        @Override
        public Fragment getItem(int position) {
            //return PlaceholderFragment.newInstance(position + 1);
            return fragments.get(position);
        }

        @Override
        public int getCount() {
            // Show 3 total pages.
            //return 3;
            return this.fragments.size();
        }

        public void addFragment(Fragment xfragment){
            this.fragments.add(xfragment);
        }

        /* //COMENTARIOS
        @Override
        public CharSequence getPageTitle(int position) {
            Locale l = Locale.getDefault();
            switch (position) {
                case 0:
                    return getString(R.string.title_section1).toUpperCase(l);
                case 1:
                    return getString(R.string.title_section2).toUpperCase(l);
                case 2:
                    return getString(R.string.title_section3).toUpperCase(l);
            }
            return null;
        }*/
    }

    public static class PlaceholderFragment extends Fragment {
        /**
         Agregue "color"
         */
        private static final String ARG_SECTION_NUMBER = "section_number";
        private static final String BACKGROUND_COLOR = "color";

        private int section_number;
        private int color;

        public static PlaceholderFragment newInstance(int sectionNumber, int color) {

            PlaceholderFragment fragment = new PlaceholderFragment();   //instanciamos un nuevo fragment

            Bundle args = new Bundle();                                 //guardamos los parametros
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            args.putInt(BACKGROUND_COLOR, color); //agrego ademas el color de fondo
            fragment.setArguments(args);
            fragment.setRetainInstance(true);     //agrego para que no se pierda los valores de la instancia
            return fragment;
        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            //cuando crea una instancia de tipo PlaceholderFragment
            //si lo enviamos parametros, guarda esos
            //si no le envio nada, toma el color gris y un número aleatroio
            if(getArguments() != null){
                this.section_number = getArguments().getInt(ARG_SECTION_NUMBER);
                this.color = getArguments().getInt(BACKGROUND_COLOR);
            }
            else{
                this.color = Color.GRAY;
                this.section_number = (int)(Math.random() * 5);
            }

        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_my, container, false);

            TextView tv_section = (TextView) rootView.findViewById(R.id.tv_section_label);
            tv_section.setText("" + section_number);
            rootView.setBackgroundColor(this.color);

            return rootView;
        }
    }

}


       
 

colors.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="white">#FFffffff</color>
    <color name="black">#FF000000</color>
    <color name="gray">#FF8c8c8c</color>
    <color name="android_blue">#FF33b5e5</color>
    <color name="android_darkblue">#FF0099cc</color>
    <color name="android_green">#FF99cc00</color>
    <color name="android_darkgreen">#FF669900</color>
    <color name="android_red">#FFff4444</color>
    <color name="android_darkred">#FFcc0000</color>
    <color name="android_yellow">#FFffd75a</color>
    <color name="android_darkyellow">#FFffc40d</color>
    <color name="android_orange">#FFffbb33</color>
    <color name="android_darkorange">#FFff8800</color>
    <color name="android_pink">#FFd9698c</color>
    <color name="android_darkpink">#FFc3325f</color>
    <color name="android_purple">#FFaa66cc</color>
    <color name="android_darkpurple">#FF9933cc</color>
</resources>

strings.xml
   <?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">ViewPager</string>
    <string name="title_section1">Section 1</string>
    <string name="title_section2">Section 2</string>
    <string name="title_section3">Section 3</string>
    <string name="hello_world">Hello world!</string>
    <string name="action_settings">Settings</string>

</resources>