How to change the new TabLayout indicator color and height

Question

Having the problem that the new TabLayout uses the indicator color from the value colorAccent, I decided to dig into the android.support.design.widget.TabLayout implementation, finding that there are no public methods to customize this. However I found this style specification of the TabLayout:

<style name="Base.Widget.Design.TabLayout" parent="android:Widget">
    <item name="tabMaxWidth">@dimen/tab_max_width</item>
    <item name="tabIndicatorColor">?attr/colorAccent</item>
    <item name="tabIndicatorHeight">2dp</item>
    <item name="tabPaddingStart">12dp</item>
    <item name="tabPaddingEnd">12dp</item>
    <item name="tabBackground">?attr/selectableItemBackground</item>
    <item name="tabTextAppearance">@style/TextAppearance.Design.Tab</item>
    <item name="tabSelectedTextColor">?android:textColorPrimary</item>
</style>

Having this style specification, now we can customize the TabLayout like this:

<android.support.design.widget.TabLayout
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@id/pages_tabs"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimary"
    android:minHeight="?attr/actionBarSize"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    app:tabIndicatorColor="@android:color/white"
    app:tabIndicatorHeight="4dp"/>

And problem solved, both the tab indicator color and height can be changed from their default values.

With the design support library you can now change them in the xml:

To change the color of the TabLayout indicator:

app:tabIndicatorColor="@color/color"

To change the height of the TabLayout indicator:

app:tabIndicatorHeight="4dp"

Since I can't post a follow-up to android developer's comment, here's an updated answer for anyone else who needs to programmatically set the selected tab indicator color:

tabLayout.setSelectedTabIndicatorColor(Color.parseColor("#FFFFFF"));

Similarly, for height:

tabLayout.setSelectedTabIndicatorHeight((int) (2 * getResources().getDisplayMetrics().density));

These methods were only recently added to revision 23.0.0 of the Support Library, which is why Soheil Setayeshi's answer uses reflection.

app:tabIndicatorColor="@android:color/white"

With the desing support library v23 you can set programmatically the color and the height.

Just use for the height:

TabLayout.setSelectedTabIndicatorHeight(int height)

Here the official javadoc.

Just use for the color:

TabLayout.setSelectedTabIndicatorColor(int color)

Here the official javadoc.

Here you can find the info in the Google Tracker.

To change indicator color and height programmatically you can use reflection. for example for indicator color use code below:

        try {
            Field field = TabLayout.class.getDeclaredField("mTabStrip");
            field.setAccessible(true);
            Object ob = field.get(tabLayout);
            Class<?> c = Class.forName("android.support.design.widget.TabLayout$SlidingTabStrip");
            Method method = c.getDeclaredMethod("setSelectedIndicatorColor", int.class);
            method.setAccessible(true);
            method.invoke(ob, Color.RED);//now its ok
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

and to change indicator height use "setSelectedIndicatorHeight" instead of "setSelectedIndicatorColor" then invoke it by your desired height