JSFiddle - React, Tailwind, and code Playground

HTML

<div class="highlighted brown">Link 1</div><br><br>

<div class="highlighted green">Link 1</div>

CSS

.brown {background-color: rgba(118,76,41,.8);}
.green {background-color: rgba(51,91,11,.8);}

JavaScript

$(document).on({
			
			mouseenter: function() {
			
			var rgba_str = $(this).css("background-color");
			var new_rgba_str ="rgba(" + rgba_str.substring(rgba_str.lastIndexOf("(")+1,rgba_str.lastIndexOf(",")) + ", 0.5)";	
               
				$(this).css("background-color",new_rgba_str ); 
	           },
    
	         mouseleave: function(){
	        
	        	 var rgba_str = $(this).css("background-color");
                
			var new_rgba_str ="rgba(" + rgba_str.substring(rgba_str.lastIndexOf("(")+1,rgba_str.lastIndexOf(",")) + ", 0.8)";				
				$(this).css("background-color",new_rgba_str ); 

	           }
     
		},'.highlighted');