Caption background-color

I want my captions without a background-color. In the options I set all options to No and in my css I added : .camera_caption, .camera_caption_title { background-color: transparent !important;}
I tried other things to, like overriding the themes > default > camera.css classes with !important but I still see the dark background. Can you please tell me where this is defined?
Edit: like often when I describe a problem correctly I can think of a solution myself: .camera_caption > div {
background-color: transparent !important;
}