Hello Matt-2,
If this can help, you can add the following css inside the additional css section of your customizer;
@media screen and (max-width: 768px){
/* menu colors */
ul.mobilemenu > li {
background-color: #363e36;
}
ul.mobilemenu > li a:active {
background-color: #466f73;
}
ul.mobilemenu ul.sub-menu {
background-color: #466f73;
}
/* footer border lines */
.lr_widgets_bottom_widget ul li {
border-bottom: 1px solid #466f73;
}
}
Regarding footer color you can go to Dashboard>> Customize>> Footer Settings>> Color Settings and make changes or else locate exactly what changes you want to make.
Note: Please change the color code of your own.
Thanks!