Change colour of menu item when on sub-menu page

CMS & WordPress
1

I am building a site in Wordpress using Starkers theme. I have used html to code the main and sub navigations and styled in css. What I am needing to do is make each of the main nav links to change color when on their page and for the parent of the sub menu to be a different color when on their pages. I have tried using current-menu-item and current-parent-item, but neither work. Any ideas??? http://page12.com.au/sample.html

My code:

    nav ul {
    list-style: none;
    font-size: 25px;
    font-family: 'HelveticaNeuel';
    color: rgb(146, 148, 151);
    }

nav ul li {
	display: block;
	float: left;
	margin-top: 40px;
	font-family: 'HelveticaNeuel';
	color: rgb(146, 148, 151);
}

/*position home, folio, contact */

nav ul li.right a {
	margin-left: 600px;
}

nav ul li.left1 a {
	margin-left: 20px;
}

nav ul li.center {
	margin-left: 40px;
}

nav ul li a {
	text-decoration: none;
	font-family: 'HelveticaNeuel';
	color: rgb(146, 148, 151);
}

nav a:hover {
	color: rgb(164, 130, 46);
}

nav ul li ul {
	display: none;
	font-size: 15px;
	padding: 10px;
	width: 800px;
}

nav ul li:hover ul {
	display: block;
	position: absolute;
	/*left: 0;*/
}

nav ul li ul li {
	padding: 10px;
}

/* sub navigation */

#sub-nav {
	width: 960px;
	height: 35px;
	text-align: right;
	padding: 5px 0 0 0;
	margin-bottom: 20px;
	font-size: 16px;
	height: 30px;
}

	#sub-nav li {
		display: inline;
		margin-left: 10px;
		margin-right: 10px;
		position: relative;
		float: left;
	}
	
	#sub-nav a {
		text-decoration: none;
		font-family: 'HelveticaNeuel';
		color: rgb(146, 148, 151);
	}
	
	#sub-nav a:active {
		color: rgb(164, 130, 46);
	}
	
	/*sub menu selected page font colour change */
	#sub-nav li.selected a {
		color: rgb(164, 130, 46);
	}

Any help appreciated.
Vicki