.ui-wysiwyg .controls ul li img { 
opacity: 1; 
-webkit-transition: opacity .5s; 
-moz-transition: opacity .5s; 
transition: opacity .5s; 
} 
.ui-wysiwyg .controls ul:hover li img { 
opacity: .5; 
} 
.ui-wysiwyg .controls ul:hover li img:hover { 
opacity: 1; 
}