JSFiddle - React, Tailwind, and code Playground

HTML

<div class="item">a
</div>

<div class="item">b
</div>

<div class="item">c
</div>

<div class="item">3
</div>

<div class="item">f
</div>

<div class="item">d
</div>

CSS

//For test
.item {
    width:100px;
    height:20px;
    display:block;
}

.red {
    background-color:red;
}

.black {
    background-color:black;
}

//for test

JavaScript

$(".item").eq(1).css("background-color","#c00");
$(".item").eq(2).css("background-color","#c00");

$(".item).mouseover(function(){
   $(".item).each(fucntion(){
       if ($(this).data('color') == '#c00'){
           $(this).css("background-color", "#F90").data('color', '#F90');
       }
   })
});