JSFiddle - React, Tailwind, and code Playground

HTML

<div class="d1"></div >
<div class="d2"></div >
<div class="d3"></div >
<div class="d4"></div >
<div class="d5"></div >

CSS

div {
    width: 50px;
    height: 50px;
    background: red;
    display: inline-block;
}

.d2, .d3, .d5 {
    background-color: #eb2c33
}

.jcbg {
    background-color: green;
}

JavaScript

function hex2rgb(hex) {
  return ['0x' + hex[1] + hex[2] | 0, '0x' + hex[3] + hex[4] | 0, '0x' + hex[5] + hex[6] | 0];
}

$(document).ready(function (e) {
    
    // Color to change
    var targetHex = hex2rgb('#eb2c33');
    
    $('body *').each(function(index) {         
        var rgbg = $(this).css('background-color');
      
        if(rgbg == 'rgb('+targetHex[0]+', '+targetHex[1]+', '+targetHex[2]+')'){
            $(this).addClass('jcbg');
        }

    });
});