remove all clasees which contain following style : how do i remove all classes which contain the following style...

**HTML**

    <div class="viewed" style="background:#F9F0D5">
    					<div class="left">
    				<span class="title">My </span>
    					<p>MPA </p>
    					</div>
    					<div class="right">
    					<span>5</span>
    					</div>
    		        	</div>



**code sample**

    document.getElementsByClassName('viewed')[0].style.background:#F9F0D5)[0].remove();