a:link {
  color: yellow;
  background-color: transparent;
  text-decoration: underline;
}

a:visited {
  color: yellow;
  background-color: transparent;
  text-decoration: underline;
}

a:hover {
  color: greenyellow;
  background-color: transparent;
  text-decoration: underline;
}

a:active {
  color: green;
  background-color: transparent;
  text-decoration: underline;
}