What you want to do is add an onchange part to your inputs to handle when the user changes the values of your input sliders. This is what it would look like:
<input id="red" name="red" type="range" min="0" max="255" step="1" value="128" onchange="changeColor()"></input>
<label for="red">red</label>
<br>
<input id="green" name="green" type="range" min="0" max="255" step="1" value="128" onchange="changeColor()"></input>
<label for="green">green</label>
<br>
<input id="blue" name="blue" type="range" min="0" max="255" step="1" value="128" onchange="changeColor()"></input>
<label for="blue">blue</label>
Now you want to make a function that will actually change the background color:
function changeColor(){
var red = document.getElementById("red").value;
var green = document.getElementById("green").value;
var blue = document.getElementById("blue").value;
document.body.style.background = "rgb(" + red + "," + green + "," + blue + ")";
}
solved Set background color to value of range input [closed]