<style>
#box {
width: 120px;
height: 80px;
border:1px solid red;
}
</style>
<div id="box"></div>
Colora <input onclick="colora(this.checked)" type="checkbox" name="colora"/>
<script>
function colora(spunta){
var div = document.getElementById("box");
if(spunta === true)
div.style.backgroundColor = "yellow";
else
div.style.backgroundColor = "";
}
</script>