Change line color in tabs - ActionBarSherlock

I'm using ActionBarSherlock to make my app compatible with older devices. The implementation was easy, but now i need to style the default Holo blue line that you see under the tabs to a red line.

I've been reading a few topics (topic 1, topic 2) here on SO and also the ABS doc (link), but i can't get it to work.

This is what i have so far.

In my AndroidManifest.xml i added this line to the application tag.

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/Theme.Sherlock" > <!-- SET THE DEFAULT THEME -->

Then in res/values/styles.xml i have:

<resources>
    <style name="AppTheme" parent="android:Theme.Light" />

    <style name="Theme.MyTheme" parent="Theme.Sherlock">
        <item name="actionBarStyle">@style/Widget.MyTheme.ActionBar</item>
        <item name="android:actionBarStyle">@style/Widget.MyTheme.ActionBar</item>
    </style>

    <style name="Widget.MyTheme.ActionBar" parent="Widget.Sherlock.ActionBar">
        <item name="android:background">#ff000000</item>
        <item name="background">#ff000000</item>
    </style>
</resources>

But when i run my app, then i still see the default blue line color.

What am i doing wrong?

EDIT

Read this if you want to fully style your ActionBarSherlock!

I found an answer here on SO which gave the following link: http://jgilfelt.github.com/android-actionbarstylegenerator

It's an easy generator which generates all the needed files for a fully customized ABS! All you have to do is copy the generated files into the appropiate folders and you're set!

Don't forget to enable the style (you'll have to enter a style name in the generator) in your AndroidManifest. For that, see the answer below.