grayScale + opacity CSS Transition

grayscaletransition.css

.class{
  opacity: 0.8;
  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%); /* Chrome 19+, Safari 6+, Safari 6+ iOS */
  /*CSS Transition*/
    -webkit-transition: all 0,2s ;
    -moz-transition: all 0,2s ;
    -ms-transition: all 0,2s ;
    -o-transition: all 0,2s ;
    transition: all 0,2s ;
}

.class:hover{
  opacity: 1; 
  filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'1 0 0 0 0, 0 1 0 0 0, 0 0 1 0 0, 0 0 0 1 0\'/></filter></svg>#grayscale");
    -webkit-filter: grayscale(0%);  
  /*CSS Transition*/
    -webkit-transition: all 0,2s ;
    -moz-transition: all 0,2s ;
    -ms-transition: all 0,2s ;
    -o-transition: all 0,2s ;
    transition: all 0,2s ;
};

This code was used on http://www.quierocambiarmedepega.cl/us