i would create two xml drawables one for each state of the btn:(saved to your drawable folder)
rounded_btn_black.xml
<?xml version="1.0" encoding="utf-8"?>
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle"
android:color="@color/black">
<size
android:height="100dp"
android:width="10dp" />
<corners
android:radius="15dp"
/>
<solid
android:color="@color/black" />
</shape>
another one for orange just changing the color
and then create a selector xml file rounded_button.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/rounded_btn_black" android:state_pressed="true" />
<item android:drawable="@drawable/rounded_btn_black" android:state_focused="true" />
<item android:drawable="@drawable/rounded_btn_orange" android:state_enabled="true" />
<item android:drawable="@drawable/rounded_btn_orange" />
</selector>
then in your layout:
<Button
android:id="@+id/login"
android:layout_width="fill_parent"
android:layout_height="@dimen/standard_btn_height"
android:layout_alignParentBottom="true"
android:layout_marginBottom="@dimen/standard_margin"
android:layout_marginLeft="@dimen/standard_margin"
android:layout_marginRight="@dimen/standard_margin"
android:background="@drawable/rounded_button"
android:text="@string/alreadyRegisterd"
android:textColor="@color/white" >
</Button>