a:link {
color: green;
background-color: transparent;
text-decoration: none;
}
a:visited {
color: black;
background-color: transparent;
text-decoration: none;
}
a:hover {
color: grey;
background-color: transparent;
text-decoration: none;
}
a:active {
color: yellow;
background-color: transparent;
text-decoration: none;
}