you can customize your tab title with color as well as Lower case by using below code
<android.support.design.widget.TabLayout
android:id="@+id/sliding_tabs"
style="@style/customTabLayout"
android:layout_width="match_parent"
android:layout_height="@dimen/tabHeight"
android:background="@color/blurred_black"
android:divider="@drawable/blue"
android:stretchColumns="*"
app:tabMode="fixed" />
customTabLayout is style which is written in style.xml file
<style name="customTabLayout" parent="Widget.Design.TabLayout">
<item name="tabIndicatorColor">@color/default_back</item>
<item name="tabIndicatorHeight">2dp</item>
<item name="tabPaddingStart">12dp</item>
<item name="tabPaddingEnd">12dp</item>
<item name="textAllCaps">false</item>
<item name="android:dividerPadding">3dp</item>
<item name="android:textSize">18sp</item>
<item name="android:textColor">@color/default_back</item>
<item name="android:divider">@android:color/black</item>
<item name="tabBackground">?attr/selectableItemBackground</item>
<item name="tabSelectedTextColor">@color/default_back</item>
</style>
Hope will help it out in other way.