JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/OwlCarousel2/2.3.2/assets/owl.carousel.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/OwlCarousel2/2.3.2/assets/owl.theme.default.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/OwlCarousel2/2.3.2/owl.carousel.min.js"></script>
<div class="owl-carousel owl-theme">
    <div class="item"><h4>1</h4></div>
    <div class="item"><h4>2</h4></div>
    <div class="item"><h4>3</h4></div>
    <div class="item"><h4>4</h4></div>
    <div class="item"><h4>5</h4></div>
    <div class="item"><h4>6</h4></div>
    <div class="item"><h4>7</h4></div>
    <div class="item"><h4>8</h4></div>
    <div class="item"><h4>9</h4></div>
    <div class="item"><h4>10</h4></div>
    <div class="item"><h4>11</h4></div>
    <div class="item"><h4>12</h4></div>
</div>

CSS

h4 {color: green; background:red;}

.opacity {
  opacity: .6;
  color:#000;
}

JavaScript

var owl = $('.owl-carousel').owlCarousel({
    loop:false,
    margin:10,
    nav:true,
    responsive:{
        0:{
            items:1
        },
        600:{
            items:3
        },
        1000:{
            items:5
        }
    },
})

var sbAllItms = $('.owl-item.active').length;
$('.owl-carousel .owl-item.active').eq(sbAllItms - 1).addClass('opacity');

owl.on('changed.owl.carousel',function(event) {
    sbAllItms = $('.owl-item.active').length;
    $('.owl-carousel .owl-item.active').removeClass('opacity');
		$('.owl-carousel .owl-item.active').eq(sbAllItms - 1).addClass('opacity');
})