Theme for ActionBar Sherlock does not work

I have a Theme for ActionBar Sherlock like this :

<style name="AppTheme" parent="Theme.Sherlock.Light">
        <item name="android:actionMenuTextColor">@drawable/selector_actionbar_white</item>
        <item name="android:actionBarStyle">@style/AppTheme.ActionBarStyle</item>
        <item name="actionBarStyle">@style/AppTheme.ActionBarStyle</item>
    </style>

    <style name="AppTheme.ActionBarStyle" parent="Widget.Sherlock.Light.ActionBar">
        <item name="android:background">@color/blue</item>
        <item name="android:titleTextStyle">@style/AppTheme.ActionBar.TitleTextStyle</item>
        <item name="titleTextStyle">@style/AppTheme.ActionBar.TitleTextStyle</item>
    </style>

    <style name="AppTheme.ActionBar.TitleTextStyle" parent="TextAppearance.Sherlock.Widget.ActionBar.Title">
        <item name="android:textColor">@color/white</item>
        <item name="textColor">@color/white</item>
        <item name="android:textSize">30sp</item>
    </style>

In my manifest my application has theme Theme.Sherlock and my activity has theme AppTheme.

<application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/Theme.Sherlock.Light">

        <!-- Splash Activity -->
        <activity
            android:name=".Splash.SplashActivity"
            android:label="Zester"
            android:screenOrientation="portrait"
            android:theme="@style/AppTheme">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
</application>

I really don't understand why my actionBar is Dark ! Normally, background should be blue and it is black.

Thks for your help ! :)