web/web_timeline/static/src/views/timeline/timeline_view.scss

$vis-hover-background-color: linen;
$vis-weekend-background-color: #dcdcdc;
$vis-item-content-padding: 0 3px !important;

.oe_timeline_view .vis-timeline {
    .vis-grid {
        &.vis-saturday,
        &.vis-sunday {
            background: $vis-weekend-background-color;
        }
    }

    .vis-item {
        &:hover {
            background-color: $vis-hover-background-color !important;
            cursor: pointer !important;
        }
        .vis-item-overflow {
            overflow: visible;
        }
        .vis-item-content {
            padding: $vis-item-content-padding;
            &:hover {
                background-color: $vis-hover-background-color !important;
            }
        }
    }
}