Custom PreferenceCategory Headings

You should take a look at Preference.Category style:

<style name="Preference.Category">
    <item name="android:layout">@android:layout/preference_category</item>
   <item name="android:shouldDisableView">false</item>
   <item name="android:selectable">false</item>
</style>

Let’s take a look at preference_category.xml file:

<!-- Layout used for PreferenceCategory in a PreferenceActivity. -->
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    style="?android:attr/listSeparatorTextViewStyle"
    android:id="@+android:id/title"
/>

So you need to create custom theme that extends default android Theme and override listSeparatorTextViewStyle value with ListHeader style. And then apply this theme to Activity that extends PreferenceActivity .

---

Here is how you can do it.

First, in your styles.xml add next code:

<style name="PreferenceListHeader" 
       parent="@android:style/Widget.TextView.ListSeparator">

    <item name="android:textColor">#000000</item>
    <item name="android:textStyle">bold</item>
    <item name="android:textSize">12sp</item>
    <item name="android:background">#cccccc</item>
    <item name="android:paddingTop">6px</item>
    <item name="android:paddingBottom">6px</item>
    <item name="android:paddingLeft">12px</item>
</style>

<style name="Theme.Custom" parent="@android:style/Theme">
    <item name="android:listSeparatorTextViewStyle">@style/PreferenceListHeader</item>               
</style>

Then in your AndroidManifest.xml add theme to your preference acitivity:

 <activity android:name=".MyPreferencesActivity" 
           android:theme="@style/Theme.Custom" 
           ... >
 ...
 </activity>

Here is a screenshot: