Styling of AlertDialog buttons

Question

In my application I use holoeverywhere. I would like to change the appearance of AlertDialog and I got stuck on buttons below alert dialog. I took a look how things were done in holoeverywhere and I tried to modify that. Here is backtracking of my reasoning:

In theme there are atributes which define alertDialogTheme and some other stuff. We will come back later to selectableItemBackground also.

<style name="Holo.Base.Theme" parent="Theme.AppCompat">
    ...
    <item name="alertDialogTheme">@style/Holo.Theme.Dialog.Alert</item>
    ...
    <item name="buttonBarButtonStyle">?borderlessButtonStyle</item>
    ...
    <item name="selectableItemBackground">@drawable/item_background_holo_dark</item> *
    ...
</sytle>

So i figure alertDialogStyle is my target which is further defined in styles:

<style name="Holo.Base.Theme.Dialog" parent="Holo.Theme">
    <item name="android:colorBackgroundCacheHint">@null</item>
    <item name="android:windowAnimationStyle">@style/Holo.Animation.Dialog</item>
    <item name="android:windowBackground">@drawable/dialog_full_holo_dark</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowFrame">@null</item>
    <item name="android:windowIsFloating">true</item>
    <item name="android:windowSoftInputMode">stateUnspecified|adjustPan</item>
    <item name="android:windowTitleStyle">@style/Holo.DialogWindowTitle</item>
    <item name="borderlessButtonStyle">@style/Holo.Button.Borderless.Small</item>
    <item name="buttonBarStyle">@style/Holo.ButtonBar.AlertDialog</item>
    <item name="listPreferredItemPaddingLeft">16dip</item>
    <item name="listPreferredItemPaddingRight">16dip</item>
    <item name="windowActionBar">false</item>
    <item name="windowActionModeOverlay">true</item>
    <item name="windowAnimationStyle">@style/Holo.Animation.Dialog</item>
    <item name="windowContentOverlay">@null</item>
    <item name="windowMinWidthMajor">@dimen/dialog_min_width_major</item>
    <item name="windowMinWidthMinor">@dimen/dialog_min_width_minor</item>
    <item name="windowNoTitle">true</item>
</style>

<style name="Holo.Theme.Dialog" parent="Holo.Base.Theme.Dialog" >
</style>

<style name="Holo.Theme.Dialog.Alert" parent="Holo.Theme.Dialog">
    <item name="alertDialogStyle">@style/Holo.AlertDialog</item>
    <item name="alertDialogTitleDividerColor">@color/holo_blue_light</item>
    <item name="android:windowBackground">@android:color/transparent</item>
</style>

<style name="Holo.Button.Borderless" parent="Holo.Button">
    <item name="android:background">?selectableItemBackground</item>
    <item name="android:paddingLeft">4dip</item>
    <item name="android:paddingRight">4dip</item>
</style>

So Holo.Theme.Dialog.Alert is inherited from Holo:base.Theme.Dialog which has an atribute for borderlessButtonStyle, which I guess defines the buttons of alert dialog. Style Holo.Button.Borderless referes the atribute selectableItemBackground for its background. Atribute is set in application theme itself. So, my reasoning is if I inherit from theme Holo.theme and set selectableBackground atribut my change should reflect in customized alert dialog buttons and everything else where this background is used.

<style name="ThemeCustom" parent="@style/Holo.Theme>
… 
<item name="selectableItemBackground">@drawable/custom_item_background </item>
…
</style>

But this does not work. No change is visible in alert dialog buttons. Is there something wrong with my reasoning?