Mobile Menu Color Issues.

Currently, my client has a black header and dark grey mobile menu (3 horizontal dashes).
He wishes to keep the black background — that being said, my CSS commands do not seem to be altering the Mobile menu ANY. Here is the code I am using via the Highend options>>GeneralSetings>>Custom CSS:

#header-inner.nav-type-2 #show-nav-menu {
color: white !important;
}

I was under the impression that the type-2 #show-nav-menu referenced the mobile drop down — however I must be mistaken!

Please Help!

Thanks!