JSFiddle - React, Tailwind, and code Playground

HTML

<div id="maFen" align="center";>       
        
         <input name="monBouton" id="monBouton" type="button" onClick="$();"value="Afficher Mot" />
         
         <input name="monBouton2" id="monBouton2" type="button" onClick="$();"value="Afficher nom de la couleur" />

JavaScript

$(document).ready(function() { 

$('#monBouton').click(function() {

var myval = $('#maFen').append('<span id = "monMot" >' +"Mot" +'</span>');
$("#monMot").css({"background-color": "#C0C0C0"});
//$(monBouton).attr("disabled", "disabled");

});

$('#monBouton2').click(function() {

			couleur=rgb2hex($("#monMot").css("background-color"));
      alert (couleur); 
				 if(couleur=="#c0c0c0") {
         //if(couleur=="rgb(192,192,192)") {
         //if ($("#monMot").css("background-color")=="rgb(192,192,192)")   {
         //if ($("#monMot").isBgcolor("#C0C0C0"))   {     
         //if($("#monMot").attr('background-color','#C0C0C0')=true) {
          alert ("Couleur Grise"); 
           //$("#monMot").text("Word");  
             
            
         //$("#monMot").text("Word");
     }

});


function rgb2hex(orig){
 var rgb = orig.replace(/\s/g,'').match(/^rgba?\((\d+),(\d+),(\d+)/i);
 return (rgb && rgb.length === 4) ? "#" +
  ("0" + parseInt(rgb[1],10).toString(16)).slice(-2) +
  ("0" + parseInt(rgb[2],10).toString(16)).slice(-2) +
  ("0" + parseInt(rgb[3],10).toString(16)).slice(-2) : orig;
}
});