My initial issue is with the responsive menu changing its colour to white (usual dark grey menu on desktop layout) and I cannot seem to find the settings for the responsive menu.

Also my client wishes for a centrally aligned menu header (logo and navigation centred) Could you please inform me what would be the best way of doing this ?

Thank you for your time.

I see, you can easily switch the responsive header color with some CSS, I would be happy to help with that, let me see your URL so I can see how far you got.

As for the center logo and nav, do you mean you want them one on top of the other? If yes, check your “Main Navigation Block Style” option in Theme options.

@media only screen and (max-width: 768px){
#header {
    background: rgba(59,59, 60, 1);
}
.block_header #logo {
    float: left;
}
.m_nav_ham {
    background: #fff;
}
}

Let me know once you do!

@media only screen and (max-width: 768px){
#header {
    background: rgba(59,59, 60, 1) !important;
}
.block_header #logo {
    float: left;
}
.m_nav_ham {
    background: #fff;
}
}

( I will probably be pestering you in the future)