com.android.support:appcompat-v7:21+
added support for tinting widgets on devices running pre android 5.1 (API Level 21). To make use of it make sure you extend or set the AppCompat
Theme and use app:backgroundTint
instead of android:backgroundTint
.
Example:
<android.support.design.widget.FloatingActionButton
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:src="https://stackoverflow.com/questions/30870443/@drawable/icon"
app:backgroundTint="@color/accent"
app:borderWidth="0dp" />