Question Detail

if You want to change color You need to use Customize Icon for this.
try this :   drawable/indicatorcustome.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">
   <item android:drawable="@drawable/ic_up" 
         android:state_empty="true" />
   <item android:drawable="@drawable/ic_down" 
         android:state_expanded="true" />
</selector>

<ExpandableListView android:id="@+id/android:list"
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"
    android:layout_marginTop="10dp"
    android:groupIndicator="@drawable/indicatorcustome" />