jellyfin-web/dashboard-ui/themes/halloween/style.css

.ui-body-b h1, .ui-body-b h2 {
    color: #FF9100;
}

.viewMenuBar, .halloweenInfoButton {
    color: #FF9100 !important;
}

.barsMenuButton {
    color: #FF9100 !important;
}

.libraryViewNav .ui-btn-active {
    border-bottom-color: #FF9100 !important;
    color: #FF9100 !important;
}

paper-button[raised].more {
    background: #FF9100;
}

.channelTimeslotHeader, .timeslotHeader {
    background: #FF9100 !important;
}

.channelTimeslotHeader {
    border-right-color: #FF9100 !important;
}