.bw {

 -webkit-filter: grayscale(30%);
  -webkit-filter: grayscale(30%);
  -moz-filter: grayscale(30%);
  -ms-filter: grayscale(30%);
  -o-filter: grayscale(30%);
filter: gray;
}
 
.bw:hover {
 -webkit-filter: grayscale(0%);
  -webkit-filter: grayscale(0%);
  -moz-filter: grayscale(0%);
  -ms-filter: grayscale(0%);
  -o-filter: grayscale(0%);
filter: gray;
}
.bww img{
        transition: all 0s ease 0s;
}
.bww:hover img{
         filter: hue-rotate(180deg);
        -webkit-filter: hue-rotate(250deg);
        transition: all 0.6s ease 0s;
}