Hi RUSSEL86,
you may change the style sheet specific to the plugin. Add the style sheet content to custom CSS area and change as per your requirement. primary-menu_264 class is specific to my site, it will be different in your project.
.wr-megamenu-container.primary-menu_264 {
background: #ffffff !important;
}
.primary-menu_264 .wr-mega-menu > li:hover > a,
.primary-menu_264 .wr-mega-menu > li.focus > a {
background: #cccccc !important;
}
.primary-menu_264 .wr-mega-menu > li > a {
color: #000000 !important;
font-family: Open Sans !important;
font-size:16px !important;
font-weight:normal !important;
}
.primary-menu_264 .wr-mega-menu > li > a > i {
font-size: 16px !important;
}
.primary-menu_264 .wr-mega-menu a.caption {
color: #eb1d0e !important;
font-family: Open Sans !important;
font-size:15px !important;
font-weight:bold !important;
}
.primary-menu_264 ul.sub-menu li a,
ul.submenu-items li a {
color: #b5b0b5 !important;
font-family: Open Sans !important;
font-size:13px !important;
font-weight:bold !important;
}