How to add a scrollview edge color effect in Android Lollipop?

In lollipop the overscroll effect color can be customized with the item style colorPrimary :

<style name="MyApp" parent="Theme.AppCompat.Light">
    <item name="colorPrimary">@color/mycolor</item>
</style>

This item also affect the color of the toolbar.

The "android:colorEdgeEffect" solution works perfectly, and is much better than the previous hacks. However, it cannot be used if the edge color needs to be changed prorgrammatically.

It is possible, though, to use reflection to do so, setting the EdgeEffect objects directly in the AbsListView or ScrollView instances. For example:

EdgeEffect edgeEffectTop = new EdgeEffect(this);
edgeEffectTop.setColor(Color.RED);

EdgeEffect edgeEffectBottom = new EdgeEffect(this);
edgeEffectBottom.setColor(Color.RED);

try {
    Field f1 = AbsListView.class.getDeclaredField("mEdgeGlowTop");
    f1.setAccessible(true);
    f1.set(listView, edgeEffectTop);

    Field f2 = AbsListView.class.getDeclaredField("mEdgeGlowBottom");
    f2.setAccessible(true);
    f2.set(listView, edgeEffectBottom);
} catch (Exception e) {
    e.printStackTrace();
}

EdgeEffect.setColor() was added in Lollipop.

Same caveats as any reflection-based solution, though.

You can specify android:colorEdgeEffect in your theme to change the overscroll glow color within your entire app. By default, this inherits the primary color value set by android:colorPrimary.

res/values/themes.xml:

<style name="MyAppTheme" parent="...">
    ...
    <item name="android:colorEdgeEffect">@color/my_color</item>
</style>

Alternatively, you can modify this value for a single view using an inline theme overlay.

res/values/themes.xml:

<!-- Note that there is no parent style or additional attributes specified. -->
<style name="MyEdgeOverlayTheme">
    <item name="android:colorEdgeEffect">@color/my_color</item>
</style>

res/layout/my_layout.xml:

<ListView
    ...
    android:theme="@style/MyEdgeOverlayTheme" />