Images Grayscale to Color on Hover

Images in the feed start as grayscale and when hovered over, transition to full color.

CSS

#sbi_images .sbi_item {
  filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale"); /* Firefox 10+, Firefox on Android */
  filter: gray; /* IE6-9 */
  -webkit-filter: grayscale(100%); 
  -webkit-transition: all .6s ease; 
  -webkit-backface-visibility: hidden;
}
#sb_instagram .sbi_item:hover {
  filter: none;
  filter: none;
  -webkit-filter: grayscale(0%);
}