How to change Hestia menu background on mobile

If you'd like to change the mobile menu background color then please navigate to Appearance -> Customize -> Additional CSS section and add the following code:

@media (max-width: 768px){
/**Navbar transparent**/
.navbar.navbar-transparent{
background-color: rgba(101, 36, 36, 0.8) !important;
}
/**Navbar when scrolled and not transparent**/
.navbar.navbar-not-transparent{
background-color: rgba(101, 36, 36, 0.8) !important;
}

/**Menu items background before scroll and transparent**/
.navbar.navbar-fixed-top.navbar-transparent .navbar-collapse {
background-color: rgba(165, 99, 129, 0.8) !important;
}
/**Menu items background after scroll and not transparent**/
.navbar-not-transparent .navbar-collapse{
background-color: rgba(165, 99, 129, 0.8) !important;
}
}

You can change the colors to any color combination you wish, you can use this website to get the HEX or RGBA color code you wish: https://www.hexcolortool.com/