X-Cart forums - need help to identify a tpl please

Can someone help me find what the tpl is called and where to find it?

The one where when you go to check out, the little javascript window that pops up when you hit the " ? " next to the CVV2 input box. Inside it are 2 images of Credit Cards showing you where the CVV2 number is located.

I need to find this so I can change the background image to it, its taking on the same diamond plate background as my page and since I have it as a pattern it is conflicting with the text. I need to change this background of the javascript pop up to just plain white.

Thanks