LG Ally :: Phone App Modification

What I wanted to do was change the lg default background during a phone call to the android stock gradient as i prefer the look of it better. I extracted the phone.apk out of the /system/app directory and found that the gradient images are already there. so my question is, why is the phone not using these images and how do i change it so it does. My first thought was a meta morph theme that only changed the phone app but seeing as the images are already there i guess there's no point.