Change Main Navigation Background

Can you post a link to your site?

Are you using the primary or secondary menu?

Kadence Themes

Hey dreamstone, try pasting this into your custom css box in appearance > theme options > advanced settings:

#nav-main ul.sf-menu {
background: #333;
}

Is this what you mean? You can change the text color in theme options > menu settings. The hover color is set in theme options > basic styling > primary color.
Hope this is helpful!

Hannah