Its the .head class.  I recommend setting the style in your container.css  file or the stylesheet specific to a container if your containers are set up like that.

.

Here is the code from my Container.css, where would I need to make the change?

/*
================================
 Container Styles for DotNetNuke
================================
*/  

.containermaster_blue {
    width: 100%;
    background-color: #fefefe;
    border-right: #000099 1px solid;
    border-top: #000099 1px solid;
    border-left: #000099 1px solid;
    border-bottom: #000099 1px solid;
    -moz-border-radius-bottomleft: 15px;
    -moz-border-radius-bottomright: 15px;
    -moz-border-radius-topleft: 3px;
    -moz-border-radius-topright: 3px;
}
.containerrow1_blue {
    background-image: url(gradient_LtBlue.jpg);
}
.containerrow2_blue {
    background-color: #fefefe;
}
.ModuleTitle_MenuItem {
    border: white 0px solid; /*override borders*/   
}

.ModuleTitle_MenuItem TD {  /*TD if menu is using tables*/
    cursor: pointer;
    cursor: hand;
    color: #000099;
    font-family: Arial, Tahoma, Helvetica;
    font-size: 9pt;
    font-weight: bold;
    font-style: normal;
    height: 21px;
        white-space: nowrap;  /*Word wrapping menu item now optional*/
        padding: 1px 3px 3px 1px;   
}


.ModuleTitle_MenuIcon {
    cursor: pointer;
    cursor: hand;
    background-color: #EEEEEE;
    width: 15px;
    height: 100%;   /*override the default height for icon so that menubreaks can have heights adjusted*/
}

.ModuleTitle_SubMenu
{
    z-index: 1000;
    cursor: pointer;
    cursor: hand;
    background-color: #FFFFFF;
    filter:progid:DXImageTransform.Microsoft.Shadow(color='DimGray', Direction=135, Strength=3);
    padding: 1px 1px 1px 1px;   /*explicitly set padding for sub-menus */
}

.ModuleTitle_MenuBreak  {
    background-color: #EEEEEE;
    font-size: 1px; /*make sure you take out portal.css ModuleTitle_MenuBreak for this to work*/
}

.ModuleTitle_MenuItemSel {

    cursor: pointer;
    cursor: hand;
    color: black;
    font-family: Arial, Tahoma, Helvetica;
    font-size: 9pt;
    font-weight: bold;
    font-style: normal;
    background-color: #8B7D6B;
}
.USDarkSkinObject {
color:#000099;
}