Use a Different Color on the Submenu – Zerif Lite

Hi, I am trying to find a way to adjust my website at https://www.mchattielaw.ie so that the top menu bar can be transparent and the submenu white, but I can’t seem to find the code in the style sheet to do so.

The navbar is set up like so:

}
.navbar {
background: #FFF; opacity: .85;
border: 0;
border-radius: 0 !important;
text-align: left;
}

And I’ve tried adding a different background color under submenu and dropdownmenu, but it didn’t work. Anyone know how to do this?

Thanks in advance for your help!