Apps Theme background not totally the color chosen

[pluto20010]

I wanted to change the background of the apptheme to a color. But after applying it I am not getting the full background color as desired

This is how it is looking like

http://prntscr.com/ej4pbw

I made changes in the styles.xml

as the following code:-

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="android:background">#2D3238</item>

    </style>

</resources>

Please tell me what is the right way then to do it so I get the desired background color