jquery-siblings.html

<style>
    div {
        height: calc(100% / 12);
        background-color: black;
        margin: 1px;
    }
    
    body {
        background-color: hsl(35, 90%, 55%);
    }

</style>

<div></div>

<div style=""></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>


<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<script>
    /*
        Use each() to loop through all elements in the collection. 
        Provide each() with a function which will be run on each
        of the elements. 
    */
    
    // Add a click action to each div
    $("div").click(function(){
        // Clicking this div
        $(this)
            .css({backgroundColor:"black"}) // Sets the background color to black
            .siblings()                     // filter the selection to siblings
            .css({backgroundColor:"red"});  // set the background color to red for all siblings
    });
</script>