JSFiddle - React, Tailwind, and code Playground

HTML

<input id='color' />

<input id='change' type='button' value='Change color' />

CSS

body
{
     background-color: #000;   
}

JavaScript

//For your usage - simply change 'body' to '#mycss' or whatever else you would like to change the color of.

//On Button Click
$('#change').click(function()
{
    $('body').css('background-color',$('#color').val()); 
});


//On Textbox Change
$('#color').change(function()
{
         $('body').css('background-color',$(this).val());               
});