Question [Q] Need help: where is the Emergency Call's texture in lock screen?

Hello everybody, I'm a newbie in Android modification, and a new member of this community too. Hope that I posted this thread in a right place, if not, may moderator help me to move it, thank you in advance.

These days, I tried to edit my lock screen, and I have a problem finding the box texture of the Emergency Call button: (see the "Emergency Call - Press and hold" in the bottom of the screenshots)

(So sorry, I'm new member so I can't post link or picture in thread )
i292.photobucket.com/albums/mm14/kisseshacker/Screenshot_2014-03-14-20-58-40.png

i292.photobucket.com/albums/mm14/kisseshacker/Screenshot_2014-03-14-20-58-45.png

i292.photobucket.com/albums/mm14/kisseshacker/Screenshot_2014-03-14-20-58-49.png

I think there are 3 PNG files for that button, the first (in the 1st screenshot) is a grey rounded rectangle, the second (2nd screenshot) is a light-blue rounded rectangle which appears when we tap on it, and the third (3rd screenshot) is a blue one which appears when we hold it (when it is released, Emegency Dialer will appear).

I tried to look for those texture but I can't find it anywhere (even in SystemUI>res>drawable-xhdpi or framework-res>res>drawable-xhdpi). Please help me if you know what are those texture's name and their place.

More information, if they are useful: my phone: LG LTE2, JB 4.1.2, rom Minimal v2.0.

Thanks in advance, I appreciate all your helps.