If you add the following line to your TabLayout
it should work:
app:tabTextAppearance="@android:style/TextAppearance.Widget.TabWidget"
Use it like this:
<android.support.design.widget.TabLayout
android:id="@+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabIndicatorColor="@android:color/white"
app:tabIndicatorHeight="2dp"
app:tabTextAppearance="@android:style/TextAppearance.Widget.TabWidget"
app:tabSelectedTextColor="@android:color/white"
app:tabTextColor="@android:color/white" />