Extend My Menu Colors Across Page

I recommend you contact the developer of your theme.

Thanks Bloke. Is there any CSS forums where I can go to learn how to do this myself that you might recommend?

If you’re not using a Child Theme, and if the theme doesn’t have a designated section of the dashboard for CSS modifications then install this Custom CSS Manager plugin https://www.ads-software.com/plugins/custom-css-manager-plugin

Then use its “CSS Code” section of the dashboard to hold your CSS modifications:

Alternatively use your Child Theme style.css file to hold your CSS modifications:

@media screen and (min-width: 990px) {
    body {
        overflow-x: hidden;
    }

    .nav-primary .wrap {
        position: relative;
    }

    .nav-primary .wrap:before,
    .nav-primary .wrap:after {
        background: #00A18A;
        content: "";
        height: 59px;
        position: absolute;
        top: 0;
        width: 100%;
    }

    .nav-primary .wrap:before {
        left: -100%;
    }

    .nav-primary .wrap:after {
        right: -100%;
    }
}

This is awesome. Thank you so much!