img { filter: gray; /* IE6-9 */ filter: grayscale(1); /* Firefox 35+ */ -webkit-filter: grayscale(1); /* Google Chrome, Safari 6+ & Opera 15+ */ } /* Disable grayscale on hover */ img:hover { filter: none; -webkit-filter: grayscale(0); } This code uses css filters. When added to the style.css file, Wordpress'a turns all pictures (which are described by a tag) into gray, and when you hover the mouse, it shows colors. But the problem is that it acts equally on all the pictures on the page. Is it possible to make it work only in one sidebar? Thank you for attention.