How to create RGB color generator using HTML CSS and JavaScript ?

function myColour() {

    // Get the value of red color
    var red = document.getElementById('red').value;

    // Get the value of green color
    var green = document.getElementById('green').value;

    // Get the value of blue color
    var blue = document.getElementById('blue').value;

    // rgb() function is used to create the color
    // from red, green and blue values
    var colour = 'rgb(' + red + ',' + green + ',' + blue + ')';

    // Change background colour with the 
    // color obtained by rgb function
    document.body.style.backgroundColor = colour;

    // Set the obtained rgb() colour code in the
    // input text field having id=box  
    document.getElementById('box').value = colour;

}

// On changing red range slider myColour()
// function is called  
document.getElementById('red')
    .addEventListener('input', myColour);

// On changing green range slider myColour()
// function is called
document.getElementById('green')
    .addEventListener('input', myColour);

// On changing blue range slider myColour()
// function is called
document.getElementById('blue')
    .addEventListener('input', myColour);