maxim1978,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.item {
width: 40px;
height: 40px;
}
.red {
background: red;
}
.green {
background: green;
}
.blue {
background: blue;
}
.yellow {
background: yellow;
}
</style>
<script>
document.addEventListener( "click" , function(event) {
let item = event.target.closest('.item');
if(!item) return;
document.body.style.backgroundColor = item.classList[1];
//document.body.style.backgroundColor = getComputedStyle(item).backgroundColor;
});
</script>
</head>
<body>
<div class="item red"></div>
<div class="item green"></div>
<div class="item blue"></div>
<div class="item yellow"></div>
</body>
</html>