Menu on mobile

ok i’ve changed the color to white, but that’s changed the 3 lines, err… can I change the three lines to #000000 ?

Not sure I fully understand your question, can you point out which 3 lines you want the background to be black?
https://www.screencast.com/t/E0TAhEfx10Y7

Let me know :)

The 3 lines you click on to bring the menu up

Try this:

#mobile-header.toggled .main-nav > ul, #mobile-header .menu-toggle, #mobile-header .mobile-bar-items {
    background-color: #000;
}