Details:
I\'m extending ActionBarActivity.
Eclipse and SDK fully patched as of 2011-11-06.
Sometimes this option throws NullPointerException
ActionBar actionbar = getActionBar();
actionbar.setBackgroundDrawable(new ColorDrawable("color"));
But this option is worked for me. So you can try this.
getSupportActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#FFFFFF")));
Happy Coding