Try this xml :
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
<item
android:bottom="10dp"
android:right="10dp">
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="#0000FF" />
</shape>
</item>
<item
android:right="10dp"
android:top="10dp">
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="#FF0000" />
</shape>
</item>
<item
android:left="10dp"
android:top="10dp">
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="#FFFF00" />
</shape>
</item>
<item
android:bottom="10dp"
android:left="10dp">
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="#00FF00" />
</shape>
</item>
<item
android:bottom="10dp"
android:left="10dp"
android:right="10dp">
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="#0000FF" />
</shape>
</item>
<item
android:bottom="10dp"
android:left="10dp"
android:right="10dp"
android:top="10dp">
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="#3f3f3f" />
</shape>
</item>
</layer-list>