Need help with mystery box in Poloray slider

Hi, I have 2 issues:

#1 - There is an empty box that appears under the slider image. Please help me get rid of it. I've attached a screen shot. It is labeled #1

#2 - How do I change the color of the call-to-action button on the homepage, beneath the slider (labeled #2 in the attached screen shot)

Thanks

 

Paste this code in Custom CSS
Appearance > Theme Option > Styling Option > Custom CSS

Code:

.slider_wrapper{
background:none;
}
.contentbtn {
background: red;
}