Change Nav background color per page..

Hi guys..

im stumped on changing my nav menu background color per page..
here is my website nothing exciting just yet.. http://www.mmotitans.com

as you can see i added a background image to the page thats black.. to go behind the slider to make it look nice and neat, my nav menu image is transparent just to make things look good.. it looks great on the home page..

But what i want to do for the rest of the pages is remove the slider and background but the nav menu looks silly with a silver background in the transparent area so i wanted to change the nav menu color a bit darker on all pages except the home page..

I’ve googled and looked up several suggestions..

the page id is 179.. ive tried editing it like

.page-id-179 #main-navigation {
background-color: #000000;
}

but its not doing anything.. any suggestions?

also.. once i figured this out id use the same idea to remove the black image too.. thanks