img.link {
  height: 50px;
  width: 50px;
  filter: grayscale(100%);
  transition-duration: 300ms;
}
img.link.website {
  filter: grayscale(100%) brightness(75%);
}
img.link.github {
  filter: grayscale(100%) brightness(50%);
}
img.link:hover {
  filter: grayscale(0%) brightness(100%);
}