How to change android design support library FAB Button border color?

you can make circle without drawable

  <android.support.design.widget.FloatingActionButton
        android:id="@+id/bottom_navigation_fab"
        style="@style/fab_material"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerInParent="true"
        android:layout_gravity="bottom|center"
        app:borderWidth="3dp"
        android:backgroundTint="@color/mountain_meadow" // inner circle color
        android:layout_marginBottom="10dp"
        android:tint="@color/white"
        app:backgroundTint="@color/white" // border color
        app:srcCompat="@drawable/bottom_nav_star" />

output :

fab.xml in drawable

<?xml version="1.0" encoding="utf-8"?>

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:innerRadius="0dp"
    android:shape="ring"
    android:thicknessRatio="2"
    android:useLevel="false" >
    <solid android:color="@android:color/transparent" />

    <stroke
        android:width="3dp"
        android:color="@android:color/white" />
</shape>

Floating Action Button in layout

<android.support.design.widget.FloatingActionButton
        android:id="@+id/buttton_float"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_action_social_notifications"
        android:background="@drawable/fab"
        android:layout_margin="@dimen/fab_margin"
        android:layout_gravity="bottom|right"
        app:fabSize="normal"
        app:backgroundTint="@android:color/white"
        app:rippleColor="@android:color/black"
        app:borderWidth="0dp"
        app:elevation="2dp"
        app:pressedTranslationZ="12dp"/>

Note : The custom design for your FAB is against the guidelines of Google Material Design for Floating Action Button