MediaWiki:Foreground.css

nav.top-bar,
.top-bar.expanded .title-area {
    background: #8D182B;
}

.client-dark-mode .top-bar.expanded .title-area {
    filter: unset;
}

#navwrapper {
    background: #8D182B;
}

ul#top-bar-left li,
ul#top-bar-left li a
 {
    background: #8D182B;
}

ul#top-bar-right li,
ul#top-bar-right li a {
    background: #8D182B;
}

ul#top-bar-left li:hover,
ul#top-bar-left li a:hover,
ul#top-bar-right li:hover:not(.has-form),
ul#top-bar-right li a:hover {
    background: #E5E5E5;
    color: #8D182B;
}

button,
.button,
.multipleTemplateAdder {
    background-color: #0645ad;
    border-color: #0645ad;
}