img {
	opacity: 0.5;
	transition: all 500ms;
	-moz-transition: all 500ms; /* Firefox 4 */
	-webkit-transition: all 500ms; /* Safari and Chrome */
	-o-transition: all 500ms; /* Opera */
}

.selected {
	border: 1px solid green;
	opacity: 1;
}

.highlighted {
	border: 1px solid red;
	opacity: 1;
}