#gallery {
  margin: 150px 400px;
}
#gallery ul { list-style: none; }
#gallery ul li { display: inline; }
#gallery ul img {
border: 0px;
}
#gallery ul a:hover img {
color: #fff;
}
#gallery ul a:hover { color: #fff; } 

body{
height: 575px;
background-color: grey;
}