Change ActionBar title text color using Light.DarkActionBar theme in AppCompat 21

You can change it with actionBarStyle attribute of theme.

<style name="AppBaseTheme" parent="@style/Theme.AppCompat.Light.DarkActionBar">
    <item name="actionBarStyle">@style/MyActionBar</item>
</style>

<style name="MyActionBar" parent="@style/Widget.AppCompat.ActionBar.Solid">
    <item name="titleTextStyle">@style/MyTitleTextStyle</item>
</style>

<style name="MyTitleTextStyle" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Title">
    <item name="android:textColor">CHANGE_COLOR_HERE</item>
</style>