safekat/httpdocs/themes/focus2/scss/layout/version-dark/_dark-right-sidebar.scss

[data-theme-version="dark"] {
    .sidebar-right {
        background-color: lighten($d-bg, 3.2%);

        .nav-tabs {
            background-color: lighten($d-bg, 3.2%);
            border-bottom: 1px solid $d-bg;

            .nav-link {
                &.active {
                    background-color: $d-bg;
                }
            }
        }
    }
}