There are many question here from people having the exact same problem as I, and I've looked though a million, tried different things for 2-3 hours now, and I still can't get it working.
Child Activity:
Intent resultIntent = new Intent(myColorPicker.this, WidgetConfig.class);
resultIntent.putExtra("key", appwidget_notecolor);
setResult(RESULT_OK, resultIntent);
finish();
Parent Activity:
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);
  // Toast does not show
  Toast.makeText(getApplicationContext(), "onActivityResult fired", Toast.LENGTH_SHORT).show();
  if (resultCode == RESULT_OK ) {
        // Toast does not show
        Toast.makeText(getApplicationContext(), "Result Recieved", Toast.LENGTH_SHORT).show();
    }
}
I launch child activity from parent activity like this:
Intent myColorPickerIntent = new Intent(WidgetConfig.this, myColorPicker.class);
myColorPickerIntent.putExtra("appwidget_notecolor", appwidget_notecolor);
WidgetConfig.this.startActivity(myColorPickerIntent);
 
     
     
     
    