How do you edit the background color of a footer on the York template?

I'm trying to figure out how to edit the background color of the footer on the York template. I've tried pasting a variety of CSS into the Design CSS editor, including the ones below... but I keep getting errors.

First one I've tried:

#page-footer-wrapper { color: white; background-color: black; a { color: white; } a:hover { color: gray; } }

The error I got was -> "error evaluating function

rgba

: color functions take numbers as parameters"

The second I've tried:

#footer { background: black !important; }

The error I got was -> "error evaluating function

rgba

: color functions take numbers as parameters"

Any help would be greatly appreciated!

Do you have a link to your site?