$(document).ready( function() {
$('#members a').css('opacity',0.5); // Set opacity to 0.5 for grayscale image

$('#members a').mouseover(function(){
//On mouseenter
$(this).stop().animate({'background-position':'0 -30px' }, "fast"); //Reveal color image
$(this).stop().animate({'opacity':1}, 'fast'); //set opacity to 1
//on mouseleave
}).mouseout(function(){
$(this).stop().animate({'background-position':'0 0' }, "fast"); //set back initial background-position for grayscale image
$(this).stop().animate({'opacity':0.5}, 'fast'); //set back initial opacity
});
});