Edit in JSFiddle

$('#first').hover(
 function() {
    $('div:not("#first")').css("background-color", "yellow");
 },

 function() {
    $('div:not("#first")').css("background-color", "white");
 }
);
 <div id="first"></div>
 <div id="second"></div> 
 <div id="third"></div> 
div {width:100px; height:100px; border:1px solid #ccc;}