How do I change the background color on one page in my website

Hi I have the My Music Band Pro theme and I am wanting to change the back ground color on one page. I have tried CSS to do this and it never changes. The site isn’t live and I don’t see a way to upload a screen shot.

Here is the CSS I have tried.

.page-id-16 {
background-color: black;
color: white;
}