fab3.xml

<android.support.design.widget.FloatingActionButton
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_add"
    app:backgroundTint="@color/orange"
    app:borderWidth="0dp"
    app:elevation="6dp"
    app:fabSize="normal" >
  
  //ถ้าจเปลียนสี icon ใช้
  android:tint="@color/white"