randomColor

<!DOCTYPE html>
<html lang="en"> <meta charset="utf-8"/>
<body id = "textId" >
<center>
    <p style = "color:red;background:white;">
        WHAT COLOR?
    </p>
    <button onclick = "changeColor()">
        Change!!!
    </button>
</center>
        <script>
    function randIntr(Hl) {
      return Math.floor(Math.random() * (Hl + 1) ) ;
   }
    function changeColor(){
        var text = document.getElementById("textId");
        text.style = "background:rgb("+randIntr(255)+","+randIntr(255)+','+randIntr(255) + ");";
    }
    </script>

</body>
</html>