android,java代码设置背景色

public class MainActivity extends Activity {

private  TextView  tv1;
private String  result_weather="";
private RelativeLayout relativeLayout;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv1=(TextView)findViewById(R.id.tv1);
tv1.setText(read());
relativeLayout=(RelativeLayout)findViewById(R.id.relativeLayout);
//	relativeLayout.setBackgroundColor(R.drawable.red);///这样不行
relativeLayout.setBackgroundColor(getResources().getColor(R.drawable.red));//////这样才可以

}..........

color.xml
<pre name="code" class="html"><?xml version="1.0" encoding="UTF-8"?>

<resources>
<drawable name="darkgray">#808080</drawable>
<drawable name="red">#F24535</drawable>
<drawable name="blue">#0000FF</drawable>
<drawable name="lightred">#90FF0000</drawable>
<drawable name="lightgray">#90505050</drawable>
</resources>