[Theme: Afterlight] Turnoff all hover effects

Hello,
I would like to turn off hover effects for all menus and side buttons.
I am using the afterlight theme and want to change the colors via the css editor to a white background and black text and black borders. I can’t make the theme menu not change the background color to white and the text lighter on hover.
The website is http://www.hellotherepress.com

.entry-date {
	display: none;
}

body {
	font-size: 24px;
	color: black;
}

h1 {
	color: black;
}

h2 {
	color: black;
}

h3 {
	color: black;
}

.main-navigation, .main-navigation ul li:hover ul {
	background: yellow;
	color: black;
}