I am trying to apply a button text color by default in styles.xml
I eventually discovered that a button is, in fact, a 9-patch image that is located at @android:drawable/btn_default in order to change the background you must modify this image. In order to change button text color I had to set a button widget style and import it into my app theme like so:
<resources xmlns:android="http://schemas.android.com/apk/res/android">
<style name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar" >
<item name="android:windowFullscreen">true</item>
<item name="android:windowBackground">@color/black</item>
<item name="android:textColor">@color/green</item>
<item name="android:buttonStyle">@style/ButtonText</item>
</style>
<style name="ButtonText" parent="@android:style/Widget.Button">
<item name="android:textColor">@color/green</item>
<item name="android:background">@android:drawable/btn_default</item><!-- only way to change this is to change the src image -->
<item name="android:layout_width">80.0px</item>
<item name="android:layout_height">40.0px</item>
</style>
</resources>