title: changing Color of an ActionBar in several Activities
body: <p>I have been stuck with this problem for a few hours. So here it is. I have 2 different activities. The first one has a menu with with the following options:blue,red,green,orange,purple. As soon as I click one of them the background color of the ActionBar of the first Activity changes with no problem. Now the issue starts when I try to do it for the second activity as well. so in other words, with one click of an option in a menu in a single Activity, change both ActionBars background colors in both Activities.</p>
  
  <pre><code>public class MainActivity extends Activity {
      private static String Hex;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
          Button all_notes= (Button) findViewById(R.id.All_Notes);
          all_notes.setOnClickListener(new OnClickListener() {
  
              @Override
              public void onClick(View v) {
                  Intent intent =new Intent(MainActivity.this,AllNotes.class);
                  startActivity(intent);
              }
          });
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          MenuInflater inflater = getMenuInflater();
          inflater.inflate(R.menu.main, menu);
          return true;
      } 
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          ActionBar bar = getActionBar();
          switch (item.getItemId()) {
              case R.id.action_search:
                  Toast.makeText(this, Hex, Toast.LENGTH_SHORT).show();
                  break;
              case R.id.action_settings:
                  Intent intent_1= new Intent(MainActivity.this,Settings.class);
                  startActivity(intent_1);
                  break;
              case R.id.blue:
                  bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#0099cc")));
                  Hex="#0099cc";
                  break;
              case R.id.pruple:
                  bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#9933cc")));
                  Hex="#9933cc";
                  break;
              case R.id.orange:
                  bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#FFBB33")));
                  Hex="#FFBB33";
                  break; 
              case R.id.red:
                  bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#CC0000")));
                  Hex="#CC0000";
                  break;
              case R.id.green:
                  bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#669900")));
                  Hex="#669900";
                  break;
              default:
                  bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#FFBB33")));
                  Hex="#FFBB33";
                  break;
          }
          return true;
      }
      public String getHex()
      {
          return Hex;
      }
  }
  
  
  public class Settings extends Activity{
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          // TODO Auto-generated method stub
          super.onCreate(savedInstanceState);
          MainActivity MA=new MainActivity();
          ActionBar bar=getActionBar();
          bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor(MA.getHex())));
      }
  }
  </code></pre>
  
  <p>So here you can see that I have Mainactivity which deals with the menu and allows the user input to select a color and Setting which takes the user selected color through the getHex method and changes its respective ActionBar background. 
  This obviously does not work. And I have tried to find a simple and pretty code that can do this without success. Any help is welcome. </p>