How can I modify ripple color when using ?attr/selectableItemBackground as background?

Finally I find the solution: instead of using android:colorControlHighlight directly in theme SelectableItemBackground, I should write another style:

<style name="SelectableItemTheme">
    <item name="colorControlHighlight">@color/ripple_color</item>
</style>

Then:

<style name="SelectableItemBackground">
    <item name="android:theme">@style/SelectableItemTheme</item>
    <item name="android:background">?attr/selectableItemBackground</item>
</style>

Finally add style="@style/SelectableItemBackground" to View in layout.xml.

UPDATED ON 2016/8/26
After N’s release, I found that sometimes we cannot use this method to set ripple color for some kind of View(for example, the CardView). Now I highly recommend developers using RippleDrawable, which can also be declared in xml. Here is an example:

I want to show a ripple effect when user touches/clicks a CardView above API21, and of course there should be another kind of feedback before Lollipop. So I should write:

<android.support.v7.widget.CardView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:foreground="@drawable/selectable_item_background"/>

and selectable_item_background in drawable folder:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="false" android:drawable="@android:color/transparent" />
    <item android:drawable="@color/color_clicked" />
</selector>

selectable_item_background in drawable-v21 folder:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/ripple_black" />
</selector>

finally, the ripple_black in drawable(or drawable-v21) folder:

<ripple
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:color="@color/color_clicked"
    tools:ignore="NewApi" /> <!--you can remove this line if it's in v21 folder-->

That’s it. For other views, maybe you should use android:background="@drawable/selectable_item_background". Don’t forget to set an OnClickListener, OnTouchListener or something like those for them, otherwise ripple won’t show.